999406030321 has 4 divisors (see below), whose sum is σ = 999408151012.
Its totient is φ = 999403909632.
The previous prime is 999406030313. The next prime is 999406030333. The reversal of 999406030321 is 123030604999.
999406030321 is a nontrivial binomial coefficient, being equal to C(1413794, 2).
It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 123030604999 = 887 ⋅138704177.
It can be written as a sum of positive squares in 2 ways, for example, as 210622252096 + 788783778225 = 458936^2 + 888135^2
It is a 3-Lehmer number, since φ(999406030321) divides (999406030321-1)3.
It is a cyclic number.
It is not a de Polignac number, because 999406030321 - 23 = 999406030313 is a prime.
It is not an unprimeable number, because it can be changed into a prime (999406030351) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (23) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1 + ... + 1413793.
It is an arithmetic number, because the mean of its divisors is an integer number (249852037753).
It is a Poulet number, since it divides 2999406030320-1.
Almost surely, 2999406030321 is an apocalyptic number.
999406030321 is the 1413793-rd triangular number and also the 706897-th hexagonal number.
999406030321 is the 471265-th centered nonagonal number.
It is an amenable number.
999406030321 is a deficient number, since it is larger than the sum of its proper divisors (2120691).
999406030321 is a wasteful number, since it uses less digits than its factorization.
999406030321 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 2120690.
The product of its (nonzero) digits is 314928, while the sum is 46.
The spelling of 999406030321 in words is "nine hundred ninety-nine billion, four hundred six million, thirty thousand, three hundred twenty-one".