131664421 has 6 divisors (see below), whose sum is σ = 153160710. Its totient is φ = 112855176.

The previous prime is 131664419. The next prime is 131664451. The reversal of 131664421 is 124466131.

It can be written as a sum of positive squares in only one way, i.e., 129072321 + 2592100 = 11361^2 + 1610^2 .

It is not a de Polignac number, because 131664421 - 2¹ = 131664419 is a prime.

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 131664421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131664451) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1343466 + ... + 1343563.

It is an arithmetic number, because the mean of its divisors is an integer number (25526785).

Almost surely, 2^131664421 is an apocalyptic number.

It is an amenable number.

131664421 is a deficient number, since it is larger than the sum of its proper divisors (21496289).

131664421 is an equidigital number, since it uses as much as digits as its factorization.

131664421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2687043 (or 2687036 counting only the distinct ones).

The product of its digits is 3456, while the sum is 28.

The square root of 131664421 is about 11474.5117978936. The cubic root of 131664421 is about 508.7324938890.

The spelling of 131664421 in words is "one hundred thirty-one million, six hundred sixty-four thousand, four hundred twenty-one".