21488565 has 32 divisors (see below), whose sum is σ = 40654080. Its totient is φ = 9483264.

The previous prime is 21488557. The next prime is 21488573. The reversal of 21488565 is 56588412.

It is an interprime number because it is at equal distance from previous prime (21488557) and next prime (21488573).

It is not a de Polignac number, because 21488565 - 2³ = 21488557 is a prime.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 484 + ... + 6573.

It is an arithmetic number, because the mean of its divisors is an integer number (1270440).

Almost surely, 2^21488565 is an apocalyptic number.

It is an amenable number.

21488565 is a deficient number, since it is larger than the sum of its proper divisors (19165515).

21488565 is a wasteful number, since it uses less digits than its factorization.

21488565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7101.

The product of its digits is 76800, while the sum is 39.

The square root of 21488565 is about 4635.5760159877. The cubic root of 21488565 is about 278.0155823434.

The spelling of 21488565 in words is "twenty-one million, four hundred eighty-eight thousand, five hundred sixty-five".