21403230 has 32 divisors (see below), whose sum is σ = 52623648. Its totient is φ = 5568000.

The previous prime is 21403229. The next prime is 21403241. The reversal of 21403230 is 3230412.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 7471 + ... + 9930.

It is an arithmetic number, because the mean of its divisors is an integer number (1644489).

Almost surely, 2^21403230 is an apocalyptic number.

21403230 is an abundant number, since it is smaller than the sum of its proper divisors (31220418).

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

21403230 is a wasteful number, since it uses less digits than its factorization.

21403230 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17452.

The product of its (nonzero) digits is 144, while the sum is 15.

The square root of 21403230 is about 4626.3625020095. The cubic root of 21403230 is about 277.6470772974.

Adding to 21403230 its reverse (3230412), we get a palindrome (24633642).

The spelling of 21403230 in words is "twenty-one million, four hundred three thousand, two hundred thirty".