661585356 has 18 divisors (see below), whose sum is σ = 1672340852. Its totient is φ = 220528440.

The previous prime is 661585333. The next prime is 661585367. The reversal of 661585356 is 653585166.

661585356 is a `hidden beast` number, since 6 + 61 + 58 + 535 + 6 = 666.

It is a tau number, because it is divible by the number of its divisors (18).

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 9188650 + ... + 9188721.

Almost surely, 2^661585356 is an apocalyptic number.

It is an amenable number.

661585356 is an abundant number, since it is smaller than the sum of its proper divisors (1010755496).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661585356 is a wasteful number, since it uses less digits than its factorization.

661585356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18377381 (or 18377376 counting only the distinct ones).

The product of its digits is 648000, while the sum is 45.

The square root of 661585356 is about 25721.3016000357. The cubic root of 661585356 is about 871.3553349696.

The spelling of 661585356 in words is "six hundred sixty-one million, five hundred eighty-five thousand, three hundred fifty-six".