661406264 has 16 divisors (see below), whose sum is σ = 1305407400. Its totient is φ = 313297632.

The previous prime is 661406261. The next prime is 661406281. The reversal of 661406264 is 462604166.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661406261) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 2175527 + ... + 2175830.

Almost surely, 2^661406264 is an apocalyptic number.

It is an amenable number.

661406264 is a deficient number, since it is larger than the sum of its proper divisors (644001136).

661406264 is a wasteful number, since it uses less digits than its factorization.

661406264 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4351382 (or 4351378 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 35.

The square root of 661406264 is about 25717.8199698186. The cubic root of 661406264 is about 871.2767022069.

The spelling of 661406264 in words is "six hundred sixty-one million, four hundred six thousand, two hundred sixty-four".