661974064 has 20 divisors (see below), whose sum is σ = 1283546320. Its totient is φ = 330736320.

The previous prime is 661974037. The next prime is 661974083. The reversal of 661974064 is 460479166.

661974064 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×661974064² = 876419322817352192, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 661974064.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7117 + ... + 37075.

It is an arithmetic number, because the mean of its divisors is an integer number (64177316).

Almost surely, 2^661974064 is an apocalyptic number.

It is an amenable number.

661974064 is a deficient number, since it is larger than the sum of its proper divisors (621572256).

661974064 is a wasteful number, since it uses less digits than its factorization.

661974064 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31348 (or 31342 counting only the distinct ones).

The product of its (nonzero) digits is 217728, while the sum is 43.

The square root of 661974064 is about 25728.8566399675. The cubic root of 661974064 is about 871.5259536581.

The spelling of 661974064 in words is "six hundred sixty-one million, nine hundred seventy-four thousand, sixty-four".