8631157621 has 2 divisors, whose sum is σ = 8631157622. Its totient is φ = 8631157620.

The previous prime is 8631157589. The next prime is 8631157627. The reversal of 8631157621 is 1267511368.

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., 5247408721 + 3383748900 = 72439^2 + 58170^2 .

It is a cyclic number.

It is not a de Polignac number, because 8631157621 - 2⁵ = 8631157589 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (8631157627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4315578810 + 4315578811.

It is an arithmetic number, because the mean of its divisors is an integer number (4315578811).

Almost surely, 2^8631157621 is an apocalyptic number.

It is an amenable number.

8631157621 is a deficient number, since it is larger than the sum of its proper divisors (1).

8631157621 is an equidigital number, since it uses as much as digits as its factorization.

8631157621 is an evil number, because the sum of its binary digits is even.

The product of its digits is 60480, while the sum is 40.

The square root of 8631157621 is about 92904.0237072647. The cubic root of 8631157621 is about 2051.2708852492.

Adding to 8631157621 its reverse (1267511368), we get a palindrome (9898668989).

The spelling of 8631157621 in words is "eight billion, six hundred thirty-one million, one hundred fifty-seven thousand, six hundred twenty-one".