16721530731 has 40 divisors (see below), whose sum is σ = 25803277104. Its totient is φ = 10783368000.

The previous prime is 16721530711. The next prime is 16721530739. The reversal of 16721530731 is 13703512761.

It is not a de Polignac number, because 16721530731 - 2¹⁸ = 16721268587 is a prime.

It is a super-2 number, since 2×16721530731² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16721530739) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 502356 + ... + 534606.

Almost surely, 2^16721530731 is an apocalyptic number.

16721530731 is a deficient number, since it is larger than the sum of its proper divisors (9081746373).

16721530731 is a wasteful number, since it uses less digits than its factorization.

16721530731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32473 (or 32464 counting only the distinct ones).

The product of its (nonzero) digits is 26460, while the sum is 36.

The spelling of 16721530731 in words is "sixteen billion, seven hundred twenty-one million, five hundred thirty thousand, seven hundred thirty-one".