661286976 has 56 divisors (see below), whose sum is σ = 1999609920. Its totient is φ = 188938752.

The previous prime is 661286933. The next prime is 661286987. The reversal of 661286976 is 679682166.

It is a tau number, because it is divible by the number of its divisors (56).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 244671 + ... + 247358.

It is an arithmetic number, because the mean of its divisors is an integer number (35707320).

Almost surely, 2^661286976 is an apocalyptic number.

It is an amenable number.

661286976 is an abundant number, since it is smaller than the sum of its proper divisors (1338322944).

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

661286976 is a wasteful number, since it uses less digits than its factorization.

661286976 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 492051 (or 492041 counting only the distinct ones).

The product of its digits is 1306368, while the sum is 51.

The square root of 661286976 is about 25715.5006951061. The cubic root of 661286976 is about 871.2243193222.

The spelling of 661286976 in words is "six hundred sixty-one million, two hundred eighty-six thousand, nine hundred seventy-six".