21722460 has 48 divisors (see below), whose sum is σ = 62125056. Its totient is φ = 5668672.

The previous prime is 21722429. The next prime is 21722483. The reversal of 21722460 is 6422712.

It is a self number, because there is not a number n which added to its sum of digits gives 21722460.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1032 + ... + 6671.

It is an arithmetic number, because the mean of its divisors is an integer number (1294272).

Almost surely, 2^21722460 is an apocalyptic number.

21722460 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 21722460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31062528).

21722460 is an abundant number, since it is smaller than the sum of its proper divisors (40402596).

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

21722460 is a wasteful number, since it uses less digits than its factorization.

21722460 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7762 (or 7760 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 24.

The square root of 21722460 is about 4660.7359933813. The cubic root of 21722460 is about 279.0206431200.

The spelling of 21722460 in words is "twenty-one million, seven hundred twenty-two thousand, four hundred sixty".