16721271531 has 24 divisors (see below), whose sum is σ = 25658431344. Its totient is φ = 10875617280.

The previous prime is 16721271529. The next prime is 16721271563. The reversal of 16721271531 is 13517212761.

It is not a de Polignac number, because 16721271531 - 2¹ = 16721271529 is a prime.

It is a super-2 number, since 2×16721271531² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (16721271521) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 829206 + ... + 849131.

It is an arithmetic number, because the mean of its divisors is an integer number (1069101306).

Almost surely, 2^16721271531 is an apocalyptic number.

16721271531 is a deficient number, since it is larger than the sum of its proper divisors (8937159813).

16721271531 is an equidigital number, since it uses as much as digits as its factorization.

16721271531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1678393 (or 1678381 counting only the distinct ones).

The product of its digits is 17640, while the sum is 36.

The spelling of 16721271531 in words is "sixteen billion, seven hundred twenty-one million, two hundred seventy-one thousand, five hundred thirty-one".