21330234 has 12 divisors (see below), whose sum is σ = 46215546. Its totient is φ = 7110072.

The previous prime is 21330163. The next prime is 21330251. The reversal of 21330234 is 43203312.

It can be written as a sum of positive squares in only one way, i.e., 16281225 + 5049009 = 4035^2 + 2247^2 .

It is a Harshad number since it is a multiple of its sum of digits (18), and also a Moran number because the ratio is a prime number: 1185013 = 21330234 / (2 + 1 + 3 + 3 + 0 + 2 + 3 + 4).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 592489 + ... + 592524.

Almost surely, 2^21330234 is an apocalyptic number.

21330234 is an abundant number, since it is smaller than the sum of its proper divisors (24885312).

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

21330234 is a wasteful number, since it uses less digits than its factorization.

21330234 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1185021 (or 1185018 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 18.

The square root of 21330234 is about 4618.4666286550. The cubic root of 21330234 is about 277.3310781041.

Adding to 21330234 its reverse (43203312), we get a palindrome (64533546).

It can be divided in two parts, 21330 and 234, that multiplied together give a triangular number (4991220 = T₃₁₅₉).

The spelling of 21330234 in words is "twenty-one million, three hundred thirty thousand, two hundred thirty-four".