996019521781 has 4 divisors (see below), whose sum is σ = 996524348652. Its totient is φ = 995514694912.

The previous prime is 996019521769. The next prime is 996019521797. The reversal of 996019521781 is 187125910699.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 372385534756 + 623633987025 = 610234^2 + 789705^2 .

It is a cyclic number.

It is not a de Polignac number, because 996019521781 - 2³³ = 987429587189 is a prime.

It is a super-2 number, since 2×996019521781² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (996019521481) 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, 252410476 + ... + 252414421.

It is an arithmetic number, because the mean of its divisors is an integer number (249131087163).

Almost surely, 2^996019521781 is an apocalyptic number.

It is an amenable number.

996019521781 is a deficient number, since it is larger than the sum of its proper divisors (504826871).

996019521781 is a wasteful number, since it uses less digits than its factorization.

996019521781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 504826870.

The product of its (nonzero) digits is 2449440, while the sum is 58.

The spelling of 996019521781 in words is "nine hundred ninety-six billion, nineteen million, five hundred twenty-one thousand, seven hundred eighty-one".