21490560 has 384 divisors, whose sum is σ = 93562560. Its totient is φ = 4423680.

The previous prime is 21490541. The next prime is 21490589. The reversal of 21490560 is 6509412.

21490560 is a `hidden beast` number, since 2 + 14 + 90 + 560 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×21490560² = 923688338227200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 524140 + ... + 524180.

Almost surely, 2^21490560 is an apocalyptic number.

21490560 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 21490560, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (46781280).

21490560 is an abundant number, since it is smaller than the sum of its proper divisors (72072000).

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

21490560 is a wasteful number, since it uses less digits than its factorization.

21490560 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86 (or 71 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 21490560 is about 4635.7911946075. The cubic root of 21490560 is about 278.0241857398.

Adding to 21490560 its reverse (6509412), we get a palindrome (27999972).

The spelling of 21490560 in words is "twenty-one million, four hundred ninety thousand, five hundred sixty".