31728515625 has 99 divisors (see below), whose sum is σ = 60461424543. Its totient is φ = 16031250000.

The previous prime is 31728515569. The next prime is 31728515669. The reversal of 31728515625 is 52651582713.

The square root of 31728515625 is 178125.

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

31728515625 is a `hidden beast` number, since 3 + 1 + 7 + 2 + 8 + 5 + 15 + 625 = 666.

It can be written as a sum of positive squares in 5 ways, for example, as 182493081 + 31546022544 = 13509^2 + 177612^2 .

It is not a de Polignac number, because 31728515625 - 2¹⁷ = 31728384553 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 98 ways as a sum of consecutive naturals, for example, 1669921866 + ... + 1669921884.

Almost surely, 2^31728515625 is an apocalyptic number.

31728515625 is the 178125-th square number.

31728515625 is the 89063-rd centered octagonal number.

It is an amenable number.

31728515625 is a deficient number, since it is larger than the sum of its proper divisors (28732908918).

31728515625 is an frugal number, since it uses more digits than its factorization.

31728515625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94 (or 27 counting only the distinct ones).

The product of its digits is 504000, while the sum is 45.

The spelling of 31728515625 in words is "thirty-one billion, seven hundred twenty-eight million, five hundred fifteen thousand, six hundred twenty-five".