21954100 has 72 divisors (see below), whose sum is σ = 55274240. Its totient is φ = 7413120.

The previous prime is 21954059. The next prime is 21954103. The reversal of 21954100 is 145912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21954103) 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, 55102 + ... + 55498.

Almost surely, 2^21954100 is an apocalyptic number.

21954100 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 21954100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27637120).

21954100 is an abundant number, since it is smaller than the sum of its proper divisors (33320140).

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

21954100 is a wasteful number, since it uses less digits than its factorization.

21954100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 497 (or 490 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 21954100 is about 4685.5202485957. The cubic root of 21954100 is about 280.0089282867.

The spelling of 21954100 in words is "twenty-one million, nine hundred fifty-four thousand, one hundred".