66161551011680 has 48 divisors (see below), whose sum is σ = 156989226204720. Its totient is φ = 26349054362112.

The previous prime is 66161551011649. The next prime is 66161551011719. The reversal of 66161551011680 is 8611015516166.

It is a happy number.

It is a super-2 number, since 2×66161551011680² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

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, 902822954 + ... + 902896233.

It is an arithmetic number, because the mean of its divisors is an integer number (3270608879265).

Almost surely, 2^{66161551011680} is an apocalyptic number.

It is an amenable number.

66161551011680 is an abundant number, since it is smaller than the sum of its proper divisors (90827675193040).

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

66161551011680 is a wasteful number, since it uses less digits than its factorization.

66161551011680 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1805719431 (or 1805719423 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 47.

The spelling of 66161551011680 in words is "sixty-six trillion, one hundred sixty-one billion, five hundred fifty-one million, eleven thousand, six hundred eighty".