16323990521 has 8 divisors (see below), whose sum is σ = 16767087624. Its totient is φ = 15880993920.

The previous prime is 16323990499. The next prime is 16323990577. The reversal of 16323990521 is 12509932361.

It can be written as a sum of positive squares in 4 ways, for example, as 7054152121 + 9269838400 = 83989^2 + 96280^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 16323990521 - 2⁶ = 16323990457 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16323990821) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 400631 + ... + 439491.

It is an arithmetic number, because the mean of its divisors is an integer number (2095885953).

Almost surely, 2^16323990521 is an apocalyptic number.

It is an amenable number.

16323990521 is a deficient number, since it is larger than the sum of its proper divisors (443097103).

16323990521 is a wasteful number, since it uses less digits than its factorization.

16323990521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50251.

The product of its (nonzero) digits is 87480, while the sum is 41.

The spelling of 16323990521 in words is "sixteen billion, three hundred twenty-three million, nine hundred ninety thousand, five hundred twenty-one".