668101890625 has 63 divisors (see below), whose sum is σ = 906099319749. Its totient is φ = 492386700000.

The previous prime is 668101890607. The next prime is 668101890661. The reversal of 668101890625 is 526098101866.

The square root of 668101890625 is 817375.

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

It can be written as a sum of positive squares in 10 ways, for example, as 313419705921 + 354682184704 = 559839^2 + 595552^2 .

It is not a de Polignac number, because 668101890625 - 2²³ = 668093502017 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 1328234124 + ... + 1328234626.

Almost surely, 2^668101890625 is an apocalyptic number.

668101890625 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

668101890625 is the 817375-th square number.

668101890625 is the 408688-th centered octagonal number.

It is an amenable number.

668101890625 is a deficient number, since it is larger than the sum of its proper divisors (237997429124).

668101890625 is an frugal number, since it uses more digits than its factorization.

668101890625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1062 (or 521 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 52.

The spelling of 668101890625 in words is "six hundred sixty-eight billion, one hundred one million, eight hundred ninety thousand, six hundred twenty-five".