22121540 has 36 divisors (see below), whose sum is σ = 54042156. Its totient is φ = 7584192.

The previous prime is 22121531. The next prime is 22121543. The reversal of 22121540 is 4512122.

It can be written as a sum of positive squares in 2 ways, for example, as 4008004 + 18113536 = 2002^2 + 4256^2 .

It is not an unprimeable number, because it can be changed into a prime (22121543) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10307 + ... + 12266.

It is an arithmetic number, because the mean of its divisors is an integer number (1501171).

Almost surely, 2^22121540 is an apocalyptic number.

22121540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

22121540 is an abundant number, since it is smaller than the sum of its proper divisors (31920616).

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

22121540 is a wasteful number, since it uses less digits than its factorization.

22121540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22596 (or 22587 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 22121540 is about 4703.3541223259. The cubic root of 22121540 is about 280.7189855381.

Adding to 22121540 its reverse (4512122), we get a palindrome (26633662).

The spelling of 22121540 in words is "twenty-two million, one hundred twenty-one thousand, five hundred forty".