21839442 has 16 divisors (see below), whose sum is σ = 44695200. Its totient is φ = 7110432.

The previous prime is 21839437. The next prime is 21839459. The reversal of 21839442 is 24493812.

It is a super-2 number, since 2×21839442² = 953922453742728, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42067 + ... + 42582.

It is an arithmetic number, because the mean of its divisors is an integer number (2793450).

Almost surely, 2^21839442 is an apocalyptic number.

21839442 is an abundant number, since it is smaller than the sum of its proper divisors (22855758).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21839442 is a wasteful number, since it uses less digits than its factorization.

21839442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84697.

The product of its digits is 13824, while the sum is 33.

The square root of 21839442 is about 4673.2688773491. The cubic root of 21839442 is about 279.5206167995.

The spelling of 21839442 in words is "twenty-one million, eight hundred thirty-nine thousand, four hundred forty-two".