221980631 has 2 divisors, whose sum is σ = 221980632. Its totient is φ = 221980630.

The previous prime is 221980621. The next prime is 221980657. The reversal of 221980631 is 136089122.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221980631 is a prime.

It is a super-2 number, since 2×221980631² = 98550801078316322, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (221980621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 110990315 + 110990316.

It is an arithmetic number, because the mean of its divisors is an integer number (110990316).

Almost surely, 2^221980631 is an apocalyptic number.

221980631 is a deficient number, since it is larger than the sum of its proper divisors (1).

221980631 is an equidigital number, since it uses as much as digits as its factorization.

221980631 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 221980631 is about 14899.0144304917. The cubic root of 221980631 is about 605.4872844928.

The spelling of 221980631 in words is "two hundred twenty-one million, nine hundred eighty thousand, six hundred thirty-one".