631086221 has 2 divisors, whose sum is σ = 631086222. Its totient is φ = 631086220.

The previous prime is 631086217. The next prime is 631086277. The reversal of 631086221 is 122680136.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 624300196 + 6786025 = 24986^2 + 2605^2 .

It is a cyclic number.

It is not a de Polignac number, because 631086221 - 2² = 631086217 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631083221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315543110 + 315543111.

It is an arithmetic number, because the mean of its divisors is an integer number (315543111).

Almost surely, 2^631086221 is an apocalyptic number.

It is an amenable number.

631086221 is a deficient number, since it is larger than the sum of its proper divisors (1).

631086221 is an equidigital number, since it uses as much as digits as its factorization.

631086221 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3456, while the sum is 29.

The square root of 631086221 is about 25121.4295174459. The cubic root of 631086221 is about 857.7542909890.

The spelling of 631086221 in words is "six hundred thirty-one million, eighty-six thousand, two hundred twenty-one".