66705377631 has 32 divisors (see below), whose sum is σ = 100525017600. Its totient is φ = 39092981760.

The previous prime is 66705377551. The next prime is 66705377663. The reversal of 66705377631 is 13677350766.

It is not a de Polignac number, because 66705377631 - 2¹⁰ = 66705376607 is a prime.

It is a super-2 number, since 2×66705377631² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (51).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66705377831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 415986 + ... + 553583.

It is an arithmetic number, because the mean of its divisors is an integer number (3141406800).

Almost surely, 2^66705377631 is an apocalyptic number.

66705377631 is a deficient number, since it is larger than the sum of its proper divisors (33819639969).

66705377631 is a wasteful number, since it uses less digits than its factorization.

66705377631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 969679.

The product of its (nonzero) digits is 3333960, while the sum is 51.

The spelling of 66705377631 in words is "sixty-six billion, seven hundred five million, three hundred seventy-seven thousand, six hundred thirty-one".