31916409590521 has 9 divisors (see below), whose sum is σ = 33055095664461. Its totient is φ = 30815685557664.

The previous prime is 31916409590491. The next prime is 31916409590627. The reversal of 31916409590521 is 12509590461913.

The square root of 31916409590521 is 5649461.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 29381730921 + 31887027859600 = 171411^2 + 5646860^2 .

It is not a de Polignac number, because 31916409590521 - 2⁵ = 31916409590489 is a prime.

It is a super-2 number, since 2×31916409590521² (a number of 28 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31916409596521) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 163736965 + ... + 163931773.

Almost surely, 2^{31916409590521} is an apocalyptic number.

31916409590521 is the 5649461-st square number.

31916409590521 is the 2824731-st centered octagonal number.

It is an amenable number.

31916409590521 is a deficient number, since it is larger than the sum of its proper divisors (1138686073940).

31916409590521 is an frugal number, since it uses more digits than its factorization.

31916409590521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389676 (or 194838 counting only the distinct ones).

The product of its (nonzero) digits is 2624400, while the sum is 55.

The spelling of 31916409590521 in words is "thirty-one trillion, nine hundred sixteen billion, four hundred nine million, five hundred ninety thousand, five hundred twenty-one".