66731646075136 has 81 divisors (see below), whose sum is σ = 154952112924189. Its totient is φ = 28598884780032.

The previous prime is 66731646075109. The next prime is 66731646075179. The reversal of 66731646075136 is 63157064613766.

The square root of 66731646075136 is 8168944.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 64640313606400 + 2091332468736 = 8039920^2 + 1446144^2 .

It is a super-2 number, since 2×66731646075136² (a number of 28 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 914885260 + ... + 914958196.

Almost surely, 2^{66731646075136} is an apocalyptic number.

66731646075136 is the 8168944-th square number.

It is an amenable number.

66731646075136 is an abundant number, since it is smaller than the sum of its proper divisors (88220466849053).

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

66731646075136 is an frugal number, since it uses more digits than its factorization.

66731646075136 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145904 (or 72946 counting only the distinct ones).

The product of its (nonzero) digits is 68584320, while the sum is 61.

The spelling of 66731646075136 in words is "sixty-six trillion, seven hundred thirty-one billion, six hundred forty-six million, seventy-five thousand, one hundred thirty-six".