131556233621 has 8 divisors (see below), whose sum is σ = 136100645400. Its totient is φ = 127012354560.

The previous prime is 131556233593. The next prime is 131556233639. The reversal of 131556233621 is 126332655131.

It can be written as a sum of positive squares in 4 ways, for example, as 97915171396 + 33641062225 = 312914^2 + 183415^2 .

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 131556233621 - 2²⁶ = 131489124757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (131556233021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 406361 + ... + 654401.

It is an arithmetic number, because the mean of its divisors is an integer number (17012580675).

Almost surely, 2^131556233621 is an apocalyptic number.

It is an amenable number.

131556233621 is a deficient number, since it is larger than the sum of its proper divisors (4544411779).

131556233621 is a wasteful number, since it uses less digits than its factorization.

131556233621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266359.

The product of its digits is 97200, while the sum is 38.

Adding to 131556233621 its reverse (126332655131), we get a palindrome (257888888752).

The spelling of 131556233621 in words is "one hundred thirty-one billion, five hundred fifty-six million, two hundred thirty-three thousand, six hundred twenty-one".