31666558401 has 27 divisors (see below), whose sum is σ = 47834319169. Its totient is φ = 20185337832.

The previous prime is 31666558387. The next prime is 31666558409. The reversal of 31666558401 is 10485566613.

The square root of 31666558401 is 177951.

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

It is not a de Polignac number, because 31666558401 - 2⁹ = 31666557889 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (31666558409) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 12277330 + ... + 12279908.

Almost surely, 2^31666558401 is an apocalyptic number.

31666558401 is the 177951-st square number.

31666558401 is the 88976-th centered octagonal number.

It is an amenable number.

31666558401 is a deficient number, since it is larger than the sum of its proper divisors (16167760768).

31666558401 is an frugal number, since it uses more digits than its factorization.

31666558401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5210 (or 2605 counting only the distinct ones).

The product of its (nonzero) digits is 518400, while the sum is 45.

The spelling of 31666558401 in words is "thirty-one billion, six hundred sixty-six million, five hundred fifty-eight thousand, four hundred one".