22521820 has 24 divisors (see below), whose sum is σ = 48190464. Its totient is φ = 8838336.

The previous prime is 22521803. The next prime is 22521823. The reversal of 22521820 is 2812522.

It is a super-2 number, since 2×22521820² = 1014464752224800, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 22521791 and 22521800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22521823) 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, 9564 + ... + 11683.

It is an arithmetic number, because the mean of its divisors is an integer number (2007936).

Almost surely, 2^22521820 is an apocalyptic number.

22521820 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

22521820 is an abundant number, since it is smaller than the sum of its proper divisors (25668644).

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

22521820 is a wasteful number, since it uses less digits than its factorization.

22521820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21309 (or 21307 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 22521820 is about 4745.7159628448. The cubic root of 22521820 is about 282.4020387626.

The spelling of 22521820 in words is "twenty-two million, five hundred twenty-one thousand, eight hundred twenty".