20637289 has 4 divisors (see below), whose sum is σ = 21303040. Its totient is φ = 19971540.

The previous prime is 20637283. The next prime is 20637293. The reversal of 20637289 is 98273602.

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 a cyclic number.

It is not a de Polignac number, because 20637289 - 2⁵ = 20637257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20637283) 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, 332829 + ... + 332890.

It is an arithmetic number, because the mean of its divisors is an integer number (5325760).

Almost surely, 2^20637289 is an apocalyptic number.

It is an amenable number.

20637289 is a deficient number, since it is larger than the sum of its proper divisors (665751).

20637289 is an equidigital number, since it uses as much as digits as its factorization.

20637289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 665750.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 20637289 is about 4542.8283040414. The cubic root of 20637289 is about 274.2947837067.

The spelling of 20637289 in words is "twenty million, six hundred thirty-seven thousand, two hundred eighty-nine".