21590401 has 16 divisors (see below), whose sum is σ = 25534080. Its totient is φ = 17873280.

The previous prime is 21590369. The next prime is 21590411. The reversal of 21590401 is 10409512.

It is a cyclic number.

It is not a de Polignac number, because 21590401 - 2⁵ = 21590369 is a prime.

It is a super-2 number, since 2×21590401² = 932290830681602, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21590411) 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, 24765 + ... + 25621.

It is an arithmetic number, because the mean of its divisors is an integer number (1595880).

Almost surely, 2^21590401 is an apocalyptic number.

It is an amenable number.

21590401 is a deficient number, since it is larger than the sum of its proper divisors (3943679).

21590401 is an equidigital number, since it uses as much as digits as its factorization.

21590401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 984.

The product of its (nonzero) digits is 360, while the sum is 22.

The square root of 21590401 is about 4646.5472127161. The cubic root of 21590401 is about 278.4540696345.

Adding to 21590401 its reverse (10409512), we get a palindrome (31999913).

The spelling of 21590401 in words is "twenty-one million, five hundred ninety thousand, four hundred one".