66137431685 has 8 divisors (see below), whose sum is σ = 85469911800. Its totient is φ = 48839949504.

The previous prime is 66137431673. The next prime is 66137431747. The reversal of 66137431685 is 58613473166.

66137431685 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 535367044 + 65602064641 = 23138^2 + 256129^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66137431685 - 2⁸ = 66137431429 is a prime.

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, 508749410 + ... + 508749539.

It is an arithmetic number, because the mean of its divisors is an integer number (10683738975).

Almost surely, 2^66137431685 is an apocalyptic number.

66137431685 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

66137431685 is a deficient number, since it is larger than the sum of its proper divisors (19332480115).

66137431685 is a wasteful number, since it uses less digits than its factorization.

66137431685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1017498967.

The product of its digits is 2177280, while the sum is 50.

The spelling of 66137431685 in words is "sixty-six billion, one hundred thirty-seven million, four hundred thirty-one thousand, six hundred eighty-five".