661704725 has 12 divisors (see below), whose sum is σ = 895106400. Its totient is φ = 481239600.

The previous prime is 661704713. The next prime is 661704727. The reversal of 661704725 is 527407166.

It is not a de Polignac number, because 661704725 - 2⁴ = 661704709 is a prime.

It is a hoax number, since the sum of its digits (38) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661704727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1202825 + ... + 1203374.

It is an arithmetic number, because the mean of its divisors is an integer number (74592200).

Almost surely, 2^661704725 is an apocalyptic number.

It is an amenable number.

661704725 is a deficient number, since it is larger than the sum of its proper divisors (233401675).

661704725 is a wasteful number, since it uses less digits than its factorization.

661704725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2406220 (or 2406215 counting only the distinct ones).

The product of its (nonzero) digits is 70560, while the sum is 38.

The square root of 661704725 is about 25723.6219261596. The cubic root of 661704725 is about 871.4077376611.

The spelling of 661704725 in words is "six hundred sixty-one million, seven hundred four thousand, seven hundred twenty-five".