661280900 has 36 divisors (see below), whose sum is σ = 1639978368. Its totient is φ = 226724640.

The previous prime is 661280899. The next prime is 661280927. The reversal of 661280900 is 9082166.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 471644 + ... + 473043.

Almost surely, 2^661280900 is an apocalyptic number.

It is an amenable number.

661280900 is an abundant number, since it is smaller than the sum of its proper divisors (978697468).

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

661280900 is a wasteful number, since it uses less digits than its factorization.

661280900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 944708 (or 944701 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 661280900 is about 25715.3825559722. The cubic root of 661280900 is about 871.2216510025.

The spelling of 661280900 in words is "six hundred sixty-one million, two hundred eighty thousand, nine hundred".