21590460 has 144 divisors (see below), whose sum is σ = 70761600. Its totient is φ = 5311872.

The previous prime is 21590431. The next prime is 21590501. The reversal of 21590460 is 6409512.

It is a super-2 number, since 2×21590460² = 932295926023200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 201727 + ... + 201833.

It is an arithmetic number, because the mean of its divisors is an integer number (491400).

Almost surely, 2^21590460 is an apocalyptic number.

21590460 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 21590460, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35380800).

21590460 is an abundant number, since it is smaller than the sum of its proper divisors (49171140).

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

21590460 is a wasteful number, since it uses less digits than its factorization.

21590460 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200 (or 195 counting only the distinct ones).

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

The square root of 21590460 is about 4646.5535615120. The cubic root of 21590460 is about 278.4543232777.

Adding to 21590460 its reverse (6409512), we get a palindrome (27999972).

The spelling of 21590460 in words is "twenty-one million, five hundred ninety thousand, four hundred sixty".