22121800 has 24 divisors (see below), whose sum is σ = 51433650. Its totient is φ = 8848640.

The previous prime is 22121779. The next prime is 22121807. The reversal of 22121800 is 812122.

It can be written as a sum of positive squares in 3 ways, for example, as 20088324 + 2033476 = 4482^2 + 1426^2 .

It is not an unprimeable number, because it can be changed into a prime (22121807) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 55105 + ... + 55504.

Almost surely, 2^22121800 is an apocalyptic number.

22121800 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

22121800 is an abundant number, since it is smaller than the sum of its proper divisors (29311850).

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

22121800 is a wasteful number, since it uses less digits than its factorization.

22121800 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 110625 (or 110616 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

The square root of 22121800 is about 4703.3817620942. The cubic root of 22121800 is about 280.7200853206.

Adding to 22121800 its reverse (812122), we get a palindrome (22933922).

It can be divided in two parts, 2 and 2121800, that multiplied together give a square (4243600 = 2060²).

The spelling of 22121800 in words is "twenty-two million, one hundred twenty-one thousand, eight hundred".