21594242 has 8 divisors (see below), whose sum is σ = 32533500. Its totient is φ = 10749744.

The previous prime is 21594239. The next prime is 21594247. The reversal of 21594242 is 24249512.

It can be written as a sum of positive squares in 2 ways, for example, as 21335161 + 259081 = 4619^2 + 509^2 .

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

It is a super-2 number, since 2×21594242² = 932622575109128, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21594247) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 23117 + ... + 24032.

Almost surely, 2^21594242 is an apocalyptic number.

21594242 is a deficient number, since it is larger than the sum of its proper divisors (10939258).

21594242 is a wasteful number, since it uses less digits than its factorization.

21594242 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47380.

The product of its digits is 5760, while the sum is 29.

The square root of 21594242 is about 4646.9605119906. The cubic root of 21594242 is about 278.4705812726.

The spelling of 21594242 in words is "twenty-one million, five hundred ninety-four thousand, two hundred forty-two".