31578341930521 has 9 divisors (see below), whose sum is σ = 32264786712981. Its totient is φ = 30906203819772.

The previous prime is 31578341930503. The next prime is 31578341930563. The reversal of 31578341930521 is 12503914387513.

The square root of 31578341930521 is 5619461.

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

It is not a de Polignac number, because 31578341930521 - 2⁵ = 31578341930489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31578341930591) 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, 264054886 + ... + 264174448.

Almost surely, 2^{31578341930521} is an apocalyptic number.

31578341930521 is the 5619461-st square number.

31578341930521 is the 2809731-st centered octagonal number.

It is an amenable number.

31578341930521 is a deficient number, since it is larger than the sum of its proper divisors (686444782460).

31578341930521 is an frugal number, since it uses more digits than its factorization.

31578341930521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239220 (or 119610 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 52.

The spelling of 31578341930521 in words is "thirty-one trillion, five hundred seventy-eight billion, three hundred forty-one million, nine hundred thirty thousand, five hundred twenty-one".