631605213 has 12 divisors (see below), whose sum is σ = 912560220. Its totient is φ = 420958656.

The previous prime is 631605211. The next prime is 631605229. The reversal of 631605213 is 312506136.

631605213 is a `hidden beast` number, since 6 + 31 + 605 + 21 + 3 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 110944089 + 520661124 = 10533^2 + 22818^2 .

It is not a de Polignac number, because 631605213 - 2¹ = 631605211 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (631605211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 40803 + ... + 54111.

It is an arithmetic number, because the mean of its divisors is an integer number (76046685).

Almost surely, 2^631605213 is an apocalyptic number.

It is an amenable number.

631605213 is a deficient number, since it is larger than the sum of its proper divisors (280955007).

631605213 is a wasteful number, since it uses less digits than its factorization.

631605213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18588 (or 18585 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 27.

The square root of 631605213 is about 25131.7570615347. The cubic root of 631605213 is about 857.9893595759.

The spelling of 631605213 in words is "six hundred thirty-one million, six hundred five thousand, two hundred thirteen".