631705913 has 8 divisors (see below), whose sum is σ = 639203400. Its totient is φ = 624252160.

The previous prime is 631705849. The next prime is 631705931. The reversal of 631705913 is 319507136.

It can be written as a sum of positive squares in 4 ways, for example, as 147573904 + 484132009 = 12148^2 + 22003^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 631705913 - 2⁶ = 631705849 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (631705013) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18593 + ... + 40113.

It is an arithmetic number, because the mean of its divisors is an integer number (79900425).

Almost surely, 2^631705913 is an apocalyptic number.

It is an amenable number.

631705913 is a deficient number, since it is larger than the sum of its proper divisors (7497487).

631705913 is a wasteful number, since it uses less digits than its factorization.

631705913 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21867.

The product of its (nonzero) digits is 17010, while the sum is 35.

The square root of 631705913 is about 25133.7604229849. The cubic root of 631705913 is about 858.0349550077.

The spelling of 631705913 in words is "six hundred thirty-one million, seven hundred five thousand, nine hundred thirteen".