16991521368 has 32 divisors (see below), whose sum is σ = 42573438000. Its totient is φ = 5651222528.

The previous prime is 16991521367. The next prime is 16991521373. The reversal of 16991521368 is 86312519961.

It is a self number, because there is not a number n which added to its sum of digits gives 16991521368.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16991521361) 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, 777621 + ... + 799172.

Almost surely, 2^16991521368 is an apocalyptic number.

It is an amenable number.

16991521368 is an abundant number, since it is smaller than the sum of its proper divisors (25581916632).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16991521368 is a wasteful number, since it uses less digits than its factorization.

16991521368 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1577251 (or 1577247 counting only the distinct ones).

The product of its digits is 699840, while the sum is 51.

The spelling of 16991521368 in words is "sixteen billion, nine hundred ninety-one million, five hundred twenty-one thousand, three hundred sixty-eight".