21404922 has 64 divisors (see below), whose sum is σ = 53996544. Its totient is φ = 5495040.

The previous prime is 21404899. The next prime is 21404923. The reversal of 21404922 is 22940412.

It is a junction number, because it is equal to n+sod(n) for n = 21404892 and 21404901.

It is not an unprimeable number, because it can be changed into a prime (21404923) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 49218 + ... + 49650.

It is an arithmetic number, because the mean of its divisors is an integer number (843696).

Almost surely, 2^21404922 is an apocalyptic number.

21404922 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 21404922, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26998272).

21404922 is an abundant number, since it is smaller than the sum of its proper divisors (32591622).

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

21404922 is a wasteful number, since it uses less digits than its factorization.

21404922 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 563.

The product of its (nonzero) digits is 1152, while the sum is 24.

The square root of 21404922 is about 4626.5453634434. The cubic root of 21404922 is about 277.6543934280.

The spelling of 21404922 in words is "twenty-one million, four hundred four thousand, nine hundred twenty-two".