16721257516 has 6 divisors (see below), whose sum is σ = 29262200660. Its totient is φ = 8360628756.

The previous prime is 16721257513. The next prime is 16721257519. The reversal of 16721257516 is 61575212761.

It is an interprime number because it is at equal distance from previous prime (16721257513) and next prime (16721257519).

It is not an unprimeable number, because it can be changed into a prime (16721257513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2090157186 + ... + 2090157193.

Almost surely, 2^16721257516 is an apocalyptic number.

It is an amenable number.

16721257516 is a deficient number, since it is larger than the sum of its proper divisors (12540943144).

16721257516 is a wasteful number, since it uses less digits than its factorization.

16721257516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4180314383 (or 4180314381 counting only the distinct ones).

The product of its digits is 176400, while the sum is 43.

The spelling of 16721257516 in words is "sixteen billion, seven hundred twenty-one million, two hundred fifty-seven thousand, five hundred sixteen".