21919120 has 80 divisors (see below), whose sum is σ = 54960768. Its totient is φ = 8099840.

The previous prime is 21919111. The next prime is 21919123. The reversal of 21919120 is 2191912.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (21919123) 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, 96447 + ... + 96673.

Almost surely, 2^21919120 is an apocalyptic number.

21919120 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 21919120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27480384).

21919120 is an abundant number, since it is smaller than the sum of its proper divisors (33041648).

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

21919120 is a wasteful number, since it uses less digits than its factorization.

21919120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328 (or 322 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 25.

The square root of 21919120 is about 4681.7859840023. The cubic root of 21919120 is about 279.8601342274.

It can be divided in two parts, 2191 and 9120, that added together give a palindrome (11311).

The spelling of 21919120 in words is "twenty-one million, nine hundred nineteen thousand, one hundred twenty".