66513515752 has 32 divisors (see below), whose sum is σ = 127786808520. Its totient is φ = 32437442560.

The previous prime is 66513515749. The next prime is 66513515779. The reversal of 66513515752 is 25751531566.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 34620556356 + 31892959396 = 186066^2 + 178586^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1399158 + ... + 1445914.

Almost surely, 2^66513515752 is an apocalyptic number.

It is an amenable number.

66513515752 is a deficient number, since it is larger than the sum of its proper divisors (61273292768).

66513515752 is a wasteful number, since it uses less digits than its factorization.

66513515752 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51141 (or 51137 counting only the distinct ones).

The product of its digits is 945000, while the sum is 46.

The spelling of 66513515752 in words is "sixty-six billion, five hundred thirteen million, five hundred fifteen thousand, seven hundred fifty-two".