86921780625 has 45 divisors (see below), whose sum is σ = 156931804029. Its totient is φ = 46346490000.

The previous prime is 86921780599. The next prime is 86921780629. The reversal of 86921780625 is 52608712968.

The square root of 86921780625 is 294825.

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

86921780625 is a `hidden beast` number, since 8 + 6 + 9 + 2 + 1 + 7 + 8 + 0 + 625 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 6814667601 + 80107113024 = 82551^2 + 283032^2 .

It is a tau number, because it is divible by the number of its divisors (45).

It is not a de Polignac number, because 86921780625 - 2¹¹ = 86921778577 is a prime.

It is not an unprimeable number, because it can be changed into a prime (86921780629) by changing a digit.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 22109910 + ... + 22113840.

Almost surely, 2^86921780625 is an apocalyptic number.

86921780625 is the 294825-th square number.

86921780625 is the 147413-rd centered octagonal number.

It is an amenable number.

86921780625 is a deficient number, since it is larger than the sum of its proper divisors (70010023404).

86921780625 is an frugal number, since it uses more digits than its factorization.

86921780625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7888 (or 3939 counting only the distinct ones).

The product of its (nonzero) digits is 2903040, while the sum is 54.

The spelling of 86921780625 in words is "eighty-six billion, nine hundred twenty-one million, seven hundred eighty thousand, six hundred twenty-five".