21402430 has 16 divisors (see below), whose sum is σ = 44028000. Its totient is φ = 7337952.

The previous prime is 21402419. The next prime is 21402467. The reversal of 21402430 is 3420412.

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 7 ways as a sum of consecutive naturals, for example, 152805 + ... + 152944.

It is an arithmetic number, because the mean of its divisors is an integer number (2751750).

Almost surely, 2^21402430 is an apocalyptic number.

21402430 is an abundant number, since it is smaller than the sum of its proper divisors (22625570).

21402430 is a wasteful number, since it uses less digits than its factorization.

21402430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305763.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21402430 is about 4626.2760401861. The cubic root of 21402430 is about 277.6436179998.

Adding to 21402430 its reverse (3420412), we get a palindrome (24822842).

The spelling of 21402430 in words is "twenty-one million, four hundred two thousand, four hundred thirty".