661669506 has 32 divisors (see below), whose sum is σ = 1471478400. Its totient is φ = 220391280.

The previous prime is 661669499. The next prime is 661669511. The reversal of 661669506 is 605966166.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 83755 + ... + 91313.

It is an arithmetic number, because the mean of its divisors is an integer number (45983700).

Almost surely, 2^661669506 is an apocalyptic number.

661669506 is an abundant number, since it is smaller than the sum of its proper divisors (809808894).

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

661669506 is a wasteful number, since it uses less digits than its factorization.

661669506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9191 (or 9185 counting only the distinct ones).

The product of its (nonzero) digits is 349920, while the sum is 45.

The square root of 661669506 is about 25722.9373517100. The cubic root of 661669506 is about 871.3922772640.

The spelling of 661669506 in words is "six hundred sixty-one million, six hundred sixty-nine thousand, five hundred six".