661186725 has 12 divisors (see below), whose sum is σ = 1093162176. Its totient is φ = 352632880.

The previous prime is 661186717. The next prime is 661186739. The reversal of 661186725 is 527681166.

661186725 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 661186725 - 2³ = 661186717 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4407837 + ... + 4407986.

It is an arithmetic number, because the mean of its divisors is an integer number (91096848).

Almost surely, 2^661186725 is an apocalyptic number.

It is an amenable number.

661186725 is a deficient number, since it is larger than the sum of its proper divisors (431975451).

661186725 is a wasteful number, since it uses less digits than its factorization.

661186725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8815836 (or 8815831 counting only the distinct ones).

The product of its digits is 120960, while the sum is 42.

The square root of 661186725 is about 25713.5513883244. The cubic root of 661186725 is about 871.1802912747.

The spelling of 661186725 in words is "six hundred sixty-one million, one hundred eighty-six thousand, seven hundred twenty-five".