631080781 has 2 divisors, whose sum is σ = 631080782. Its totient is φ = 631080780.

The previous prime is 631080727. The next prime is 631080799. The reversal of 631080781 is 187080136.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 478953225 + 152127556 = 21885^2 + 12334^2 .

It is a cyclic number.

It is not a de Polignac number, because 631080781 - 2²³ = 622692173 is a prime.

It is a super-2 number, since 2×631080781² = 796525904295139922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631080581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315540390 + 315540391.

It is an arithmetic number, because the mean of its divisors is an integer number (315540391).

Almost surely, 2^631080781 is an apocalyptic number.

It is an amenable number.

631080781 is a deficient number, since it is larger than the sum of its proper divisors (1).

631080781 is an equidigital number, since it uses as much as digits as its factorization.

631080781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 34.

The square root of 631080781 is about 25121.3212431194. The cubic root of 631080781 is about 857.7518263513.

The spelling of 631080781 in words is "six hundred thirty-one million, eighty thousand, seven hundred eighty-one".