20653221 has 8 divisors (see below), whose sum is σ = 27568960. Its totient is φ = 13753152.

The previous prime is 20653189. The next prime is 20653229. The reversal of 20653221 is 12235602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20653221 - 2⁵ = 20653189 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 (20653229) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 385 + ... + 6438.

It is an arithmetic number, because the mean of its divisors is an integer number (3446120).

Almost surely, 2^20653221 is an apocalyptic number.

It is an amenable number.

20653221 is a deficient number, since it is larger than the sum of its proper divisors (6915739).

20653221 is a wasteful number, since it uses less digits than its factorization.

20653221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7835.

The product of its (nonzero) digits is 720, while the sum is 21.

The square root of 20653221 is about 4544.5814988841. The cubic root of 20653221 is about 274.3653507987.

Adding to 20653221 its reverse (12235602), we get a palindrome (32888823).

The spelling of 20653221 in words is "twenty million, six hundred fifty-three thousand, two hundred twenty-one".