66157520 has 80 divisors (see below), whose sum is σ = 180738432. Its totient is φ = 22202880.

The previous prime is 66157501. The next prime is 66157541. The reversal of 66157520 is 2575166.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (80).

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, 8549 + ... + 14331.

Almost surely, 2^66157520 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 66157520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90369216).

66157520 is an abundant number, since it is smaller than the sum of its proper divisors (114580912).

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

66157520 is a wasteful number, since it uses less digits than its factorization.

66157520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5820 (or 5814 counting only the distinct ones).

The product of its (nonzero) digits is 12600, while the sum is 32.

The square root of 66157520 is about 8133.7273128622. The cubic root of 66157520 is about 404.4452497222.

The spelling of 66157520 in words is "sixty-six million, one hundred fifty-seven thousand, five hundred twenty".