66521500628 has 120 divisors (see below), whose sum is σ = 135931353600. Its totient is φ = 28404604800.

The previous prime is 66521500627. The next prime is 66521500637. The reversal of 66521500628 is 82600512566.

It is a super-2 number, since 2×66521500628² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66521500627) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 212528600 + ... + 212528912.

It is an arithmetic number, because the mean of its divisors is an integer number (1132761280).

Almost surely, 2^66521500628 is an apocalyptic number.

It is an amenable number.

66521500628 is an abundant number, since it is smaller than the sum of its proper divisors (69409852972).

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

66521500628 is a wasteful number, since it uses less digits than its factorization.

66521500628 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 571 (or 536 counting only the distinct ones).

The product of its (nonzero) digits is 172800, while the sum is 41.

The spelling of 66521500628 in words is "sixty-six billion, five hundred twenty-one million, five hundred thousand, six hundred twenty-eight".