666187520 has 144 divisors (see below), whose sum is σ = 1673398272. Its totient is φ = 253808640.

The previous prime is 666187477. The next prime is 666187567. The reversal of 666187520 is 25781666.

666187520 is digitally balanced in base 6, 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 in 15 ways as a sum of consecutive naturals, for example, 4086959 + ... + 4087121.

Almost surely, 2^666187520 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 666187520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (836699136).

666187520 is an abundant number, since it is smaller than the sum of its proper divisors (1007210752).

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

666187520 is a wasteful number, since it uses less digits than its factorization.

666187520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 318 (or 304 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 666187520 is about 25810.6086716296. The cubic root of 666187520 is about 873.3711279929.

The spelling of 666187520 in words is "six hundred sixty-six million, one hundred eighty-seven thousand, five hundred twenty".