22521906 has 48 divisors (see below), whose sum is σ = 56373408. Its totient is φ = 6422400.

The previous prime is 22521901. The next prime is 22521931. The reversal of 22521906 is 60912522.

It is a self number, because there is not a number n which added to its sum of digits gives 22521906.

It is not an unprimeable number, because it can be changed into a prime (22521901) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21 + ... + 6711.

It is an arithmetic number, because the mean of its divisors is an integer number (1174446).

Almost surely, 2^22521906 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 22521906, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28186704).

22521906 is an abundant number, since it is smaller than the sum of its proper divisors (33851502).

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

22521906 is a wasteful number, since it uses less digits than its factorization.

22521906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6727 (or 6724 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 22521906 is about 4745.7250236397. The cubic root of 22521906 is about 282.4023982146.

The spelling of 22521906 in words is "twenty-two million, five hundred twenty-one thousand, nine hundred six".