21590457 has 8 divisors (see below), whose sum is σ = 32899776. Its totient is φ = 12337392.

The previous prime is 21590431. The next prime is 21590501. The reversal of 21590457 is 75409512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21590457 - 2⁷ = 21590329 is a prime.

It is a super-2 number, since 2×21590457² = 932295666937698, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21590417) 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 7 ways as a sum of consecutive naturals, for example, 514038 + ... + 514079.

It is an arithmetic number, because the mean of its divisors is an integer number (4112472).

Almost surely, 2^21590457 is an apocalyptic number.

It is an amenable number.

21590457 is a deficient number, since it is larger than the sum of its proper divisors (11309319).

21590457 is a wasteful number, since it uses less digits than its factorization.

21590457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1028127.

The product of its (nonzero) digits is 12600, while the sum is 33.

The square root of 21590457 is about 4646.5532386921. The cubic root of 21590457 is about 278.4543103806.

Adding to 21590457 its reverse (75409512), we get a palindrome (96999969).

The spelling of 21590457 in words is "twenty-one million, five hundred ninety thousand, four hundred fifty-seven".