21239593 has 8 divisors (see below), whose sum is σ = 21651336. Its totient is φ = 20832000.

The previous prime is 21239573. The next prime is 21239597. The reversal of 21239593 is 39593212.

It can be written as a sum of positive squares in 4 ways, for example, as 5929 + 21233664 = 77^2 + 4608^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 21239593 - 2⁹ = 21239081 is a prime.

It is a super-2 number, since 2×21239593² = 902240621611298, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21239597) 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, 10483 + ... + 12343.

It is an arithmetic number, because the mean of its divisors is an integer number (2706417).

Almost surely, 2^21239593 is an apocalyptic number.

It is an amenable number.

21239593 is a deficient number, since it is larger than the sum of its proper divisors (411743).

21239593 is a wasteful number, since it uses less digits than its factorization.

21239593 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2075.

The product of its digits is 14580, while the sum is 34.

The square root of 21239593 is about 4608.6432927707. The cubic root of 21239593 is about 276.9376888084.

The spelling of 21239593 in words is "twenty-one million, two hundred thirty-nine thousand, five hundred ninety-three".