666520156 has 48 divisors (see below), whose sum is σ = 1274797440. Its totient is φ = 303713280.

The previous prime is 666520123. The next prime is 666520163. The reversal of 666520156 is 651025666.

It is a congruent number.

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, 283546 + ... + 285886.

It is an arithmetic number, because the mean of its divisors is an integer number (26558280).

Almost surely, 2^666520156 is an apocalyptic number.

It is an amenable number.

666520156 is a deficient number, since it is larger than the sum of its proper divisors (608277284).

666520156 is a wasteful number, since it uses less digits than its factorization.

666520156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2494 (or 2492 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 37.

The square root of 666520156 is about 25817.0516519606. The cubic root of 666520156 is about 873.5164656197.

The spelling of 666520156 in words is "six hundred sixty-six million, five hundred twenty thousand, one hundred fifty-six".