21920500 has 48 divisors (see below), whose sum is σ = 54722304. Its totient is φ = 7514400.

The previous prime is 21920473. The next prime is 21920501. The reversal of 21920500 is 502912.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21920501) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 369 + ... + 6631.

It is an arithmetic number, because the mean of its divisors is an integer number (1140048).

Almost surely, 2^21920500 is an apocalyptic number.

21920500 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 21920500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27361152).

21920500 is an abundant number, since it is smaller than the sum of its proper divisors (32801804).

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

21920500 is a wasteful number, since it uses less digits than its factorization.

21920500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6289 (or 6277 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 21920500 is about 4681.9333613370. The cubic root of 21920500 is about 279.8660073172.

The spelling of 21920500 in words is "twenty-one million, nine hundred twenty thousand, five hundred".