21953400 has 96 divisors (see below), whose sum is σ = 77792640. Its totient is φ = 5016960.

The previous prime is 21953387. The next prime is 21953411. The reversal of 21953400 is 435912.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1587 + ... + 6813.

It is an arithmetic number, because the mean of its divisors is an integer number (810340).

Almost surely, 2^21953400 is an apocalyptic number.

21953400 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 21953400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38896320).

21953400 is an abundant number, since it is smaller than the sum of its proper divisors (55839240).

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

21953400 is a wasteful number, since it uses less digits than its factorization.

21953400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5253 (or 5244 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 24.

The square root of 21953400 is about 4685.4455497850. The cubic root of 21953400 is about 280.0059522544.

The spelling of 21953400 in words is "twenty-one million, nine hundred fifty-three thousand, four hundred".