66740321631 has 16 divisors (see below), whose sum is σ = 91884259328. Its totient is φ = 43045797600.

The previous prime is 66740321611. The next prime is 66740321677. The reversal of 66740321631 is 13612304766.

It is not a de Polignac number, because 66740321631 - 2¹⁸ = 66740059487 is a prime.

It is a super-2 number, since 2×66740321631² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 66740321631.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66740321611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 224325 + ... + 428721.

It is an arithmetic number, because the mean of its divisors is an integer number (5742766208).

Almost surely, 2^66740321631 is an apocalyptic number.

66740321631 is a deficient number, since it is larger than the sum of its proper divisors (25143937697).

66740321631 is a wasteful number, since it uses less digits than its factorization.

66740321631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 207942.

The product of its (nonzero) digits is 108864, while the sum is 39.

The spelling of 66740321631 in words is "sixty-six billion, seven hundred forty million, three hundred twenty-one thousand, six hundred thirty-one".