637997 has 4 divisors (see below), whose sum is σ = 665760. Its totient is φ = 610236.

The previous prime is 637939. The next prime is 638023. The reversal of 637997 is 799736.

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 637997 - 2⁶ = 637933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (637937) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13847 + ... + 13892.

It is an arithmetic number, because the mean of its divisors is an integer number (166440).

2⁶³⁷⁹⁹⁷ is an apocalyptic number.

It is an amenable number.

637997 is a deficient number, since it is larger than the sum of its proper divisors (27763).

637997 is a wasteful number, since it uses less digits than its factorization.

637997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27762.

The product of its digits is 71442, while the sum is 41.

The square root of 637997 is about 798.7471439699. The cubic root of 637997 is about 86.0873908844.

The spelling of 637997 in words is "six hundred thirty-seven thousand, nine hundred ninety-seven".