661504156 has 6 divisors (see below), whose sum is σ = 1157632280. Its totient is φ = 330752076.

The previous prime is 661504121. The next prime is 661504163. The reversal of 661504156 is 651405166.

It is a happy number.

661504156 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82688016 + ... + 82688023.

Almost surely, 2^661504156 is an apocalyptic number.

It is an amenable number.

661504156 is a deficient number, since it is larger than the sum of its proper divisors (496128124).

661504156 is a wasteful number, since it uses less digits than its factorization.

661504156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 165376043 (or 165376041 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 34.

The square root of 661504156 is about 25719.7230933772. The cubic root of 661504156 is about 871.3196847710.

The spelling of 661504156 in words is "six hundred sixty-one million, five hundred four thousand, one hundred fifty-six".