631616257 has 2 divisors, whose sum is σ = 631616258. Its totient is φ = 631616256.

The previous prime is 631616203. The next prime is 631616261. The reversal of 631616257 is 752616136.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 564965361 + 66650896 = 23769^2 + 8164^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-631616257 is a prime.

It is a super-2 number, since 2×631616257² = 797878192213380098, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (631616857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315808128 + 315808129.

It is an arithmetic number, because the mean of its divisors is an integer number (315808129).

Almost surely, 2^631616257 is an apocalyptic number.

It is an amenable number.

631616257 is a deficient number, since it is larger than the sum of its proper divisors (1).

631616257 is an equidigital number, since it uses as much as digits as its factorization.

631616257 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 45360, while the sum is 37.

The square root of 631616257 is about 25131.9767825772. The cubic root of 631616257 is about 857.9943603681.

The spelling of 631616257 in words is "six hundred thirty-one million, six hundred sixteen thousand, two hundred fifty-seven".