631869857 has 2 divisors, whose sum is σ = 631869858. Its totient is φ = 631869856.

The previous prime is 631869851. The next prime is 631869911. The reversal of 631869857 is 758968136.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 631215376 + 654481 = 25124^2 + 809^2 .

It is a cyclic number.

It is not a de Polignac number, because 631869857 - 2⁶ = 631869793 is a prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 631869799 and 631869808.

It is not a weakly prime, because it can be changed into another prime (631869851) 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, 315934928 + 315934929.

It is an arithmetic number, because the mean of its divisors is an integer number (315934929).

Almost surely, 2^631869857 is an apocalyptic number.

It is an amenable number.

631869857 is a deficient number, since it is larger than the sum of its proper divisors (1).

631869857 is an equidigital number, since it uses as much as digits as its factorization.

631869857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2177280, while the sum is 53.

The square root of 631869857 is about 25137.0216413958. The cubic root of 631869857 is about 858.1091759980.

The spelling of 631869857 in words is "six hundred thirty-one million, eight hundred sixty-nine thousand, eight hundred fifty-seven".