637997313 has 4 divisors (see below), whose sum is σ = 850663088. Its totient is φ = 425331540.

The previous prime is 637997291. The next prime is 637997341. The reversal of 637997313 is 313799736.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 637997313 - 2¹² = 637993217 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (637997363) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 106332883 + ... + 106332888.

It is an arithmetic number, because the mean of its divisors is an integer number (212665772).

Almost surely, 2^637997313 is an apocalyptic number.

It is an amenable number.

637997313 is a deficient number, since it is larger than the sum of its proper divisors (212665775).

637997313 is a wasteful number, since it uses less digits than its factorization.

637997313 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 212665774.

The product of its digits is 642978, while the sum is 48.

The square root of 637997313 is about 25258.6086908998. The cubic root of 637997313 is about 860.8740496252.

The spelling of 637997313 in words is "six hundred thirty-seven million, nine hundred ninety-seven thousand, three hundred thirteen".