661116204 has 36 divisors (see below), whose sum is σ = 1909891984. Its totient is φ = 188890272.

The previous prime is 661116173. The next prime is 661116233. The reversal of 661116204 is 402611166.

It is a tau number, because it is divible by the number of its divisors (36).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1311487 + ... + 1311990.

Almost surely, 2^661116204 is an apocalyptic number.

It is an amenable number.

661116204 is an abundant number, since it is smaller than the sum of its proper divisors (1248775780).

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

661116204 is a wasteful number, since it uses less digits than its factorization.

661116204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2623494 (or 2623489 counting only the distinct ones).

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

The square root of 661116204 is about 25712.1800709314. The cubic root of 661116204 is about 871.1493173267.

The spelling of 661116204 in words is "six hundred sixty-one million, one hundred sixteen thousand, two hundred four".