66615400464 has 20 divisors (see below), whose sum is σ = 172089784656. Its totient is φ = 22205133472.

The previous prime is 66615400459. The next prime is 66615400469. The reversal of 66615400464 is 46400451666.

It is an interprime number because it is at equal distance from previous prime (66615400459) and next prime (66615400469).

It is a super-2 number, since 2×66615400464² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66615400469) 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, 693910374 + ... + 693910469.

Almost surely, 2^66615400464 is an apocalyptic number.

It is an amenable number.

66615400464 is an abundant number, since it is smaller than the sum of its proper divisors (105474384192).

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

66615400464 is a wasteful number, since it uses less digits than its factorization.

66615400464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1387820854 (or 1387820848 counting only the distinct ones).

The product of its (nonzero) digits is 414720, while the sum is 42.

The spelling of 66615400464 in words is "sixty-six billion, six hundred fifteen million, four hundred thousand, four hundred sixty-four".