66813006520 has 64 divisors (see below), whose sum is σ = 162660587040. Its totient is φ = 24552460800.

The previous prime is 66813006511. The next prime is 66813006553. The reversal of 66813006520 is 2560031866.

It is a self number, because there is not a number n which added to its sum of digits gives 66813006520.

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, 194751 + ... + 414190.

Almost surely, 2^66813006520 is an apocalyptic number.

It is an amenable number.

66813006520 is an abundant number, since it is smaller than the sum of its proper divisors (95847580520).

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

66813006520 is a wasteful number, since it uses less digits than its factorization.

66813006520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 609176 (or 609172 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 37.

The spelling of 66813006520 in words is "sixty-six billion, eight hundred thirteen million, six thousand, five hundred twenty".