21899040 has 96 divisors (see below), whose sum is σ = 70652736. Its totient is φ = 5698560.

The previous prime is 21899023. The next prime is 21899047. The reversal of 21899040 is 4099812.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-3 number, since 3×21899040³ (a number of 23 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (33) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 21898992 and 21899010.

It is not an unprimeable number, because it can be changed into a prime (21899047) 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, 20110 + ... + 21170.

It is an arithmetic number, because the mean of its divisors is an integer number (735966).

Almost surely, 2^21899040 is an apocalyptic number.

21899040 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 21899040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35326368).

21899040 is an abundant number, since it is smaller than the sum of its proper divisors (48753696).

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

21899040 is a wasteful number, since it uses less digits than its factorization.

21899040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1122 (or 1114 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 33.

The square root of 21899040 is about 4679.6410118726. The cubic root of 21899040 is about 279.7746486119.

The spelling of 21899040 in words is "twenty-one million, eight hundred ninety-nine thousand, forty".