631701409 has 2 divisors, whose sum is σ = 631701410. Its totient is φ = 631701408.

The previous prime is 631701401. The next prime is 631701457. The reversal of 631701409 is 904107136.

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., 321413184 + 310288225 = 17928^2 + 17615^2 .

It is a cyclic number.

It is not a de Polignac number, because 631701409 - 2³ = 631701401 is a prime.

It is not a weakly prime, because it can be changed into another prime (631701401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315850704 + 315850705.

It is an arithmetic number, because the mean of its divisors is an integer number (315850705).

Almost surely, 2^631701409 is an apocalyptic number.

It is an amenable number.

631701409 is a deficient number, since it is larger than the sum of its proper divisors (1).

631701409 is an equidigital number, since it uses as much as digits as its factorization.

631701409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 31.

The square root of 631701409 is about 25133.6708222257. The cubic root of 631701409 is about 858.0329157684.

The spelling of 631701409 in words is "six hundred thirty-one million, seven hundred one thousand, four hundred nine".