661746725 has 24 divisors (see below), whose sum is σ = 867132000. Its totient is φ = 499573440.

The previous prime is 661746721. The next prime is 661746769. The reversal of 661746725 is 527647166.

661746725 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 661746725 - 2² = 661746721 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661746721) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 125186 + ... + 130364.

It is an arithmetic number, because the mean of its divisors is an integer number (36130500).

Almost surely, 2^661746725 is an apocalyptic number.

It is an amenable number.

661746725 is a deficient number, since it is larger than the sum of its proper divisors (205385275).

661746725 is a wasteful number, since it uses less digits than its factorization.

661746725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5477 (or 5472 counting only the distinct ones).

The product of its digits is 423360, while the sum is 44.

The square root of 661746725 is about 25724.4382834689. The cubic root of 661746725 is about 871.4261740570.

The spelling of 661746725 in words is "six hundred sixty-one million, seven hundred forty-six thousand, seven hundred twenty-five".