631582759981 has 2 divisors, whose sum is σ = 631582759982. Its totient is φ = 631582759980.

The previous prime is 631582759849. The next prime is 631582759987. The reversal of 631582759981 is 189957285136.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 602345179881 + 29237580100 = 776109^2 + 170990^2 .

It is a cyclic number.

It is not a de Polignac number, because 631582759981 - 2¹⁷ = 631582628909 is a prime.

It is a super-2 number, since 2×631582759981² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631582759987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315791379990 + 315791379991.

It is an arithmetic number, because the mean of its divisors is an integer number (315791379991).

Almost surely, 2^631582759981 is an apocalyptic number.

It is an amenable number.

631582759981 is a deficient number, since it is larger than the sum of its proper divisors (1).

631582759981 is an equidigital number, since it uses as much as digits as its factorization.

631582759981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 32659200, while the sum is 64.

The spelling of 631582759981 in words is "six hundred thirty-one billion, five hundred eighty-two million, seven hundred fifty-nine thousand, nine hundred eighty-one".