999806900256361 has 4 divisors (see below), whose sum is σ = 999806967331924. Its totient is φ = 999806833180800.

The previous prime is 999806900256323. The next prime is 999806900256377. The reversal of 999806900256361 is 163652009608999.

999806900256361 is a nontrivial binomial coefficient, being equal to C(44717042, 2).

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 746843632833600 + 252963267422761 = 27328440^2 + 15904819^2 .

It is a 3-Lehmer number, since φ(999806900256361) divides (999806900256361-1)³.

It is a cyclic number.

It is not a de Polignac number, because 999806900256361 - 2⁷ = 999806900256233 is a prime.

It is a super-2 number, since 2×999806900256361² (a number of 31 digits) contains 22 as substring.

It is a deceptive number, since it divides R_{999806900256360}.

It is not an unprimeable number, because it can be changed into a prime (999806900259361) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1 + ... + 44717041.

It is an arithmetic number, because the mean of its divisors is an integer number (249951741832981).

It is a Poulet number, since it divides 2^{999806900256360}-1.

Almost surely, 2^{999806900256361} is an apocalyptic number.

999806900256361 is the 44717041-st triangular number and also the 22358521-st hexagonal number.

999806900256361 is the 14905681-st centered nonagonal number.

It is an amenable number.

999806900256361 is a deficient number, since it is larger than the sum of its proper divisors (67075563).

999806900256361 is a wasteful number, since it uses less digits than its factorization.

999806900256361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67075562.

The product of its (nonzero) digits is 340122240, while the sum is 73.

The spelling of 999806900256361 in words is "nine hundred ninety-nine trillion, eight hundred six billion, nine hundred million, two hundred fifty-six thousand, three hundred sixty-one".