22161900 has 72 divisors (see below), whose sum is σ = 66217984. Its totient is φ = 5716800.

The previous prime is 22161889. The next prime is 22161901. The reversal of 22161900 is 916122.

It is a super-2 number, since 2×22161900² = 982299623220000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22161901) 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, 8109 + ... + 10491.

Almost surely, 2^22161900 is an apocalyptic number.

22161900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 22161900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33108992).

22161900 is an abundant number, since it is smaller than the sum of its proper divisors (44056084).

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

22161900 is a wasteful number, since it uses less digits than its factorization.

22161900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2431 (or 2424 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 22161900 is about 4707.6427222125. The cubic root of 22161900 is about 280.8896025768.

The spelling of 22161900 in words is "twenty-two million, one hundred sixty-one thousand, nine hundred".