21258442 has 8 divisors (see below), whose sum is σ = 31907232. Its totient is φ = 10622700.

The previous prime is 21258437. The next prime is 21258443. The reversal of 21258442 is 24485212.

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

It is a self number, because there is not a number n which added to its sum of digits gives 21258442.

It is not an unprimeable number, because it can be changed into a prime (21258443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4717 + ... + 8047.

It is an arithmetic number, because the mean of its divisors is an integer number (3988404).

Almost surely, 2^21258442 is an apocalyptic number.

21258442 is a deficient number, since it is larger than the sum of its proper divisors (10648790).

21258442 is a wasteful number, since it uses less digits than its factorization.

21258442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6524.

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

The square root of 21258442 is about 4610.6878011854. The cubic root of 21258442 is about 277.0195870365.

The spelling of 21258442 in words is "twenty-one million, two hundred fifty-eight thousand, four hundred forty-two".