66401565652 has 12 divisors (see below), whose sum is σ = 116298546196. Its totient is φ = 33173409600.

The previous prime is 66401565641. The next prime is 66401565653. The reversal of 66401565652 is 25656510466.

It can be written as a sum of positive squares in 2 ways, for example, as 32325882436 + 34075683216 = 179794^2 + 184596^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66401565653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6837849 + ... + 6847552.

Almost surely, 2^66401565652 is an apocalyptic number.

It is an amenable number.

66401565652 is a deficient number, since it is larger than the sum of its proper divisors (49896980544).

66401565652 is a wasteful number, since it uses less digits than its factorization.

66401565652 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13686618 (or 13686616 counting only the distinct ones).

The product of its (nonzero) digits is 1296000, while the sum is 46.

The spelling of 66401565652 in words is "sixty-six billion, four hundred one million, five hundred sixty-five thousand, six hundred fifty-two".