661161204 has 72 divisors (see below), whose sum is σ = 1890758688. Its totient is φ = 200348640.

The previous prime is 661161187. The next prime is 661161217. The reversal of 661161204 is 402161166.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 20227 + ... + 41610.

Almost surely, 2^661161204 is an apocalyptic number.

It is an amenable number.

661161204 is an abundant number, since it is smaller than the sum of its proper divisors (1229597484).

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

661161204 is a wasteful number, since it uses less digits than its factorization.

661161204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61867 (or 61853 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 661161204 is about 25713.0551276973. The cubic root of 661161204 is about 871.1690822987.

The spelling of 661161204 in words is "six hundred sixty-one million, one hundred sixty-one thousand, two hundred four".