21339442 has 4 divisors (see below), whose sum is σ = 32009166. Its totient is φ = 10669720.

The previous prime is 21339407. The next prime is 21339463. The reversal of 21339442 is 24493312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 13549761 + 7789681 = 3681^2 + 2791^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21339442.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5334859 + ... + 5334862.

Almost surely, 2^21339442 is an apocalyptic number.

21339442 is a deficient number, since it is larger than the sum of its proper divisors (10669724).

21339442 is a wasteful number, since it uses less digits than its factorization.

21339442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10669723.

The product of its digits is 5184, while the sum is 28.

The square root of 21339442 is about 4619.4633887498. The cubic root of 21339442 is about 277.3709791696.

The spelling of 21339442 in words is "twenty-one million, three hundred thirty-nine thousand, four hundred forty-two".