66131262431 has 4 divisors (see below), whose sum is σ = 71218282632. Its totient is φ = 61044242232.

The previous prime is 66131262413. The next prime is 66131262467. The reversal of 66131262431 is 13426213166.

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-66131262431 is a prime.

It is a super-2 number, since 2×66131262431² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 66131262391 and 66131262400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66131262481) 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, 2543510081 + ... + 2543510106.

It is an arithmetic number, because the mean of its divisors is an integer number (17804570658).

Almost surely, 2^66131262431 is an apocalyptic number.

66131262431 is a deficient number, since it is larger than the sum of its proper divisors (5087020201).

66131262431 is a wasteful number, since it uses less digits than its factorization.

66131262431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5087020200.

The product of its digits is 31104, while the sum is 35.

Adding to 66131262431 its reverse (13426213166), we get a palindrome (79557475597).

The spelling of 66131262431 in words is "sixty-six billion, one hundred thirty-one million, two hundred sixty-two thousand, four hundred thirty-one".