21422020 has 24 divisors (see below), whose sum is σ = 45189144. Its totient is φ = 8530176.

The previous prime is 21421997. The next prime is 21422021. The reversal of 21422020 is 2022412.

It can be written as a sum of positive squares in 4 ways, for example, as 188356 + 21233664 = 434^2 + 4608^2 .

It is not an unprimeable number, because it can be changed into a prime (21422021) 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, 2362 + ... + 6958.

It is an arithmetic number, because the mean of its divisors is an integer number (1882881).

Almost surely, 2^21422020 is an apocalyptic number.

21422020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21422020 is an abundant number, since it is smaller than the sum of its proper divisors (23767124).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21422020 is a wasteful number, since it uses less digits than its factorization.

21422020 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4839 (or 4837 counting only the distinct ones).

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

The square root of 21422020 is about 4628.3928096046. The cubic root of 21422020 is about 277.7283027737.

Adding to 21422020 its reverse (2022412), we get a palindrome (23444432).

The spelling of 21422020 in words is "twenty-one million, four hundred twenty-two thousand, twenty".