66515502506 has 16 divisors (see below), whose sum is σ = 105647064264. Its totient is φ = 31299992064.

The previous prime is 66515502433. The next prime is 66515502509. The reversal of 66515502506 is 60520551566.

66515502506 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 45642476881 + 20873025625 = 213641^2 + 144475^2 .

It is not an unprimeable number, because it can be changed into a prime (66515502509) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1352606 + ... + 1400918.

Almost surely, 2^66515502506 is an apocalyptic number.

66515502506 is a deficient number, since it is larger than the sum of its proper divisors (39131561758).

66515502506 is a wasteful number, since it uses less digits than its factorization.

66515502506 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88825.

The product of its (nonzero) digits is 270000, while the sum is 41.

The spelling of 66515502506 in words is "sixty-six billion, five hundred fifteen million, five hundred two thousand, five hundred six".