66681252531 has 6 divisors (see below), whose sum is σ = 96317364780. Its totient is φ = 44454168348.

The previous prime is 66681252487. The next prime is 66681252553. The reversal of 66681252531 is 13525218666.

66681252531 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 66681252531 - 2¹⁷ = 66681121459 is a prime.

It is a super-2 number, since 2×66681252531² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (66681252581) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 3704514021 + ... + 3704514038.

It is an arithmetic number, because the mean of its divisors is an integer number (16052894130).

Almost surely, 2^66681252531 is an apocalyptic number.

66681252531 is a deficient number, since it is larger than the sum of its proper divisors (29636112249).

66681252531 is a wasteful number, since it uses less digits than its factorization.

66681252531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7409028065 (or 7409028062 counting only the distinct ones).

The product of its digits is 518400, while the sum is 45.

The spelling of 66681252531 in words is "sixty-six billion, six hundred eighty-one million, two hundred fifty-two thousand, five hundred thirty-one".