21593081 has 8 divisors (see below), whose sum is σ = 23059200. Its totient is φ = 20175120.

The previous prime is 21593053. The next prime is 21593083. The reversal of 21593081 is 18039512.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21593081 is a prime.

It is a super-2 number, since 2×21593081² = 932522294145122, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21593083) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11111 + ... + 12908.

It is an arithmetic number, because the mean of its divisors is an integer number (2882400).

Almost surely, 2^21593081 is an apocalyptic number.

It is an amenable number.

21593081 is a deficient number, since it is larger than the sum of its proper divisors (1466119).

21593081 is a wasteful number, since it uses less digits than its factorization.

21593081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24079.

The product of its (nonzero) digits is 2160, while the sum is 29.

The square root of 21593081 is about 4646.8355899472. The cubic root of 21593081 is about 278.4655905882.

The spelling of 21593081 in words is "twenty-one million, five hundred ninety-three thousand, eighty-one".