21230842 has 16 divisors (see below), whose sum is σ = 33064200. Its totient is φ = 10212160.

The previous prime is 21230827. The next prime is 21230843. The reversal of 21230842 is 24803212.

It can be written as a sum of positive squares in 4 ways, for example, as 17065161 + 4165681 = 4131^2 + 2041^2 .

It is not an unprimeable number, because it can be changed into a prime (21230843) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22092 + ... + 23032.

Almost surely, 2^21230842 is an apocalyptic number.

21230842 is a deficient number, since it is larger than the sum of its proper divisors (11833358).

21230842 is a wasteful number, since it uses less digits than its factorization.

21230842 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1361.

The product of its (nonzero) digits is 768, while the sum is 22.

The square root of 21230842 is about 4607.6937832282. The cubic root of 21230842 is about 276.8996495574.

The spelling of 21230842 in words is "twenty-one million, two hundred thirty thousand, eight hundred forty-two".