631616309 has 2 divisors, whose sum is σ = 631616310. Its totient is φ = 631616308.

The previous prime is 631616273. The next prime is 631616341. The reversal of 631616309 is 903616136.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 625750225 + 5866084 = 25015^2 + 2422^2 .

It is a cyclic number.

It is not a de Polignac number, because 631616309 - 2⁸ = 631616053 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (631616389) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 315808154 + 315808155.

It is an arithmetic number, because the mean of its divisors is an integer number (315808155).

Almost surely, 2^631616309 is an apocalyptic number.

It is an amenable number.

631616309 is a deficient number, since it is larger than the sum of its proper divisors (1).

631616309 is an equidigital number, since it uses as much as digits as its factorization.

631616309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17496, while the sum is 35.

The square root of 631616309 is about 25131.9778171158. The cubic root of 631616309 is about 857.9943839139.

The spelling of 631616309 in words is "six hundred thirty-one million, six hundred sixteen thousand, three hundred nine".