21204234 has 32 divisors (see below), whose sum is σ = 47369280. Its totient is φ = 7030800.

The previous prime is 21204223. The next prime is 21204241. The reversal of 21204234 is 43240212.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10464 + ... + 12324.

It is an arithmetic number, because the mean of its divisors is an integer number (1480290).

Almost surely, 2^21204234 is an apocalyptic number.

21204234 is an abundant number, since it is smaller than the sum of its proper divisors (26165046).

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

21204234 is a wasteful number, since it uses less digits than its factorization.

21204234 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2083 (or 2077 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 21204234 is about 4604.8055333532. The cubic root of 21204234 is about 276.7839244259.

Adding to 21204234 its reverse (43240212), we get a palindrome (64444446).

The spelling of 21204234 in words is "twenty-one million, two hundred four thousand, two hundred thirty-four".