637987 has 4 divisors (see below), whose sum is σ = 729136. Its totient is φ = 546840.

The previous prime is 637939. The next prime is 638023. The reversal of 637987 is 789736.

637987 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 637987 - 2¹¹ = 635939 is a prime.

It is a Duffinian number.

637987 is a lucky 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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45564 + ... + 45577.

It is an arithmetic number, because the mean of its divisors is an integer number (182284).

2⁶³⁷⁹⁸⁷ is an apocalyptic number.

637987 is a deficient number, since it is larger than the sum of its proper divisors (91149).

637987 is an equidigital number, since it uses as much as digits as its factorization.

637987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91148.

The product of its digits is 63504, while the sum is 40.

The square root of 637987 is about 798.7408841420. The cubic root of 637987 is about 86.0869411026.

The spelling of 637987 in words is "six hundred thirty-seven thousand, nine hundred eighty-seven".