21285442 has 8 divisors (see below), whose sum is σ = 33316416. Its totient is φ = 10179972.

The previous prime is 21285421. The next prime is 21285463. The reversal of 21285442 is 24458212.

It is an interprime number because it is at equal distance from previous prime (21285421) and next prime (21285463).

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

It is a super-2 number, since 2×21285442² = 906140082270728, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21285442.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 231318 + ... + 231409.

It is an arithmetic number, because the mean of its divisors is an integer number (4164552).

Almost surely, 2^21285442 is an apocalyptic number.

21285442 is a deficient number, since it is larger than the sum of its proper divisors (12030974).

21285442 is a wasteful number, since it uses less digits than its factorization.

21285442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 462752.

The product of its digits is 5120, while the sum is 28.

The square root of 21285442 is about 4613.6148517188. The cubic root of 21285442 is about 277.1368167711.

The spelling of 21285442 in words is "twenty-one million, two hundred eighty-five thousand, four hundred forty-two".