20637 has 6 divisors (see below), whose sum is σ = 29822. Its totient is φ = 13752.

The previous prime is 20627. The next prime is 20639. The reversal of 20637 is 73602.

It can be written as a sum of positive squares in only one way, i.e., 15876 + 4761 = 126^2 + 69^2 .

It is not a de Polignac number, because 20637 - 2⁷ = 20509 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 14.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 20637.

It is not an unprimeable number, because it can be changed into a prime (20639) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1138 + ... + 1155.

2²⁰⁶³⁷ is an apocalyptic number.

It is an amenable number.

20637 is a deficient number, since it is larger than the sum of its proper divisors (9185).

20637 is a wasteful number, since it uses less digits than its factorization.

20637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2299 (or 2296 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 18.

The square root of 20637 is about 143.6558387258. The cubic root of 20637 is about 27.4293503313.

It can be divided in two parts, 2063 and 7, that multiplied together give a palindrome (14441).

The spelling of 20637 in words is "twenty thousand, six hundred thirty-seven".