21115593 has 16 divisors (see below), whose sum is σ = 32929600. Its totient is φ = 13335840.

The previous prime is 21115583. The next prime is 21115603. The reversal of 21115593 is 39551112.

It is an interprime number because it is at equal distance from previous prime (21115583) and next prime (21115603).

It is a de Polignac number, because none of the positive numbers 2^k-21115593 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21115573) 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, 20068 + ... + 21093.

It is an arithmetic number, because the mean of its divisors is an integer number (2058100).

Almost surely, 2^21115593 is an apocalyptic number.

It is an amenable number.

21115593 is a deficient number, since it is larger than the sum of its proper divisors (11814007).

21115593 is a wasteful number, since it uses less digits than its factorization.

21115593 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 41189 (or 41183 counting only the distinct ones).

The product of its digits is 1350, while the sum is 27.

The square root of 21115593 is about 4595.1706170718. The cubic root of 21115593 is about 276.3977017044.

The spelling of 21115593 in words is "twenty-one million, one hundred fifteen thousand, five hundred ninety-three".