637481994881 has 2 divisors, whose sum is σ = 637481994882. Its totient is φ = 637481994880.

The previous prime is 637481994857. The next prime is 637481994893. The reversal of 637481994881 is 188499184736.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 492545697856 + 144936297025 = 701816^2 + 380705^2 .

It is a cyclic number.

It is not a de Polignac number, because 637481994881 - 2¹⁸ = 637481732737 is a prime.

It is a super-2 number, since 2×637481994881² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (637481394881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 318740997440 + 318740997441.

It is an arithmetic number, because the mean of its divisors is an integer number (318740997441).

Almost surely, 2^637481994881 is an apocalyptic number.

It is an amenable number.

637481994881 is a deficient number, since it is larger than the sum of its proper divisors (1).

637481994881 is an equidigital number, since it uses as much as digits as its factorization.

637481994881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 83607552, while the sum is 68.

The spelling of 637481994881 in words is "six hundred thirty-seven billion, four hundred eighty-one million, nine hundred ninety-four thousand, eight hundred eighty-one".