21112390 has 48 divisors (see below), whose sum is σ = 42921648. Its totient is φ = 7432128.

The previous prime is 21112381. The next prime is 21112411. The reversal of 21112390 is 9321112.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 68617 + ... + 68923.

It is an arithmetic number, because the mean of its divisors is an integer number (894201).

Almost surely, 2^21112390 is an apocalyptic number.

21112390 is an abundant number, since it is smaller than the sum of its proper divisors (21809258).

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

21112390 is a wasteful number, since it uses less digits than its factorization.

21112390 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373 (or 350 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 21112390 is about 4594.8220857831. The cubic root of 21112390 is about 276.3837255147.

The spelling of 21112390 in words is "twenty-one million, one hundred twelve thousand, three hundred ninety".