16156401521 has 12 divisors (see below), whose sum is σ = 17741220480. Its totient is φ = 14703539760.

The previous prime is 16156401517. The next prime is 16156401529. The reversal of 16156401521 is 12510465161.

It is not a de Polignac number, because 16156401521 - 2² = 16156401517 is a prime.

It is a super-2 number, since 2×16156401521² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16156401529) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 661241 + ... + 685238.

It is an arithmetic number, because the mean of its divisors is an integer number (1478435040).

Almost surely, 2^16156401521 is an apocalyptic number.

It is an amenable number.

16156401521 is a deficient number, since it is larger than the sum of its proper divisors (1584818959).

16156401521 is a wasteful number, since it uses less digits than its factorization.

16156401521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1346576 (or 1346563 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 32.

Adding to 16156401521 its reverse (12510465161), we get a palindrome (28666866682).

It can be divided in two parts, 1615640 and 1521, that added together give a palindrome (1617161).

The spelling of 16156401521 in words is "sixteen billion, one hundred fifty-six million, four hundred one thousand, five hundred twenty-one".