660921825 has 48 divisors (see below), whose sum is σ = 1124372480. Its totient is φ = 342377280.

The previous prime is 660921799. The next prime is 660921857. The reversal of 660921825 is 528129066.

It is not a de Polignac number, because 660921825 - 2²² = 656727521 is a prime.

It is a super-2 number, since 2×660921825² = 873635317522661250, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 718716 + ... + 719634.

Almost surely, 2^660921825 is an apocalyptic number.

It is an amenable number.

660921825 is a deficient number, since it is larger than the sum of its proper divisors (463450655).

660921825 is a wasteful number, since it uses less digits than its factorization.

660921825 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1198 (or 1193 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 39.

The square root of 660921825 is about 25708.3998918641. The cubic root of 660921825 is about 871.0639315652.

The spelling of 660921825 in words is "six hundred sixty million, nine hundred twenty-one thousand, eight hundred twenty-five".