20653231 has 4 divisors (see below), whose sum is σ = 20681272. Its totient is φ = 20625192.

The previous prime is 20653229. The next prime is 20653267. The reversal of 20653231 is 13235602.

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

It is a cyclic number.

It is not a de Polignac number, because 20653231 - 2¹ = 20653229 is a prime.

It is a super-2 number, since 2×20653231² = 853111901478722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20653271) 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, 12885 + ... + 14398.

It is an arithmetic number, because the mean of its divisors is an integer number (5170318).

Almost surely, 2^20653231 is an apocalyptic number.

20653231 is a deficient number, since it is larger than the sum of its proper divisors (28041).

20653231 is an equidigital number, since it uses as much as digits as its factorization.

20653231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28040.

The product of its (nonzero) digits is 1080, while the sum is 22.

The square root of 20653231 is about 4544.5825990953. The cubic root of 20653231 is about 274.3653950799.

Adding to 20653231 its reverse (13235602), we get a palindrome (33888833).

The spelling of 20653231 in words is "twenty million, six hundred fifty-three thousand, two hundred thirty-one".