66431224631 has 4 divisors (see below), whose sum is σ = 66432651432. Its totient is φ = 66429797832.

The previous prime is 66431224619. The next prime is 66431224663. The reversal of 66431224631 is 13642213466.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66431224631 is a prime.

It is a super-2 number, since 2×66431224631² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66431224681) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 641120 + ... + 737493.

It is an arithmetic number, because the mean of its divisors is an integer number (16608162858).

Almost surely, 2^66431224631 is an apocalyptic number.

66431224631 is a deficient number, since it is larger than the sum of its proper divisors (1426801).

66431224631 is a wasteful number, since it uses less digits than its factorization.

66431224631 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1426800.

The product of its digits is 124416, while the sum is 38.

The spelling of 66431224631 in words is "sixty-six billion, four hundred thirty-one million, two hundred twenty-four thousand, six hundred thirty-one".