21590489 has 4 divisors (see below), whose sum is σ = 21617424. Its totient is φ = 21563556.

The previous prime is 21590431. The next prime is 21590501. The reversal of 21590489 is 98409512.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21590489 - 2¹² = 21586393 is a prime.

It is a super-2 number, since 2×21590489² = 932298430518242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21590419) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 12227 + ... + 13880.

It is an arithmetic number, because the mean of its divisors is an integer number (5404356).

Almost surely, 2^21590489 is an apocalyptic number.

It is an amenable number.

21590489 is a deficient number, since it is larger than the sum of its proper divisors (26935).

21590489 is an equidigital number, since it uses as much as digits as its factorization.

21590489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26934.

The product of its (nonzero) digits is 25920, while the sum is 38.

The square root of 21590489 is about 4646.5566821034. The cubic root of 21590489 is about 278.4544479496.

The spelling of 21590489 in words is "twenty-one million, five hundred ninety thousand, four hundred eighty-nine".