20220421 has 16 divisors (see below), whose sum is σ = 22720320. Its totient is φ = 17873280.

The previous prime is 20220407. The next prime is 20220451. The reversal of 20220421 is 12402202.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20220421 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20220451) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31126 + ... + 31768.

It is an arithmetic number, because the mean of its divisors is an integer number (1420020).

Almost surely, 2^20220421 is an apocalyptic number.

It is an amenable number.

20220421 is a deficient number, since it is larger than the sum of its proper divisors (2499899).

20220421 is a wasteful number, since it uses less digits than its factorization.

20220421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 756.

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 20220421 is about 4496.7122434063. The cubic root of 20220421 is about 272.4353116376.

Adding to 20220421 its reverse (12402202), we get a palindrome (32622623).

The spelling of 20220421 in words is "twenty million, two hundred twenty thousand, four hundred twenty-one".