21384430 has 16 divisors (see below), whose sum is σ = 38548224. Its totient is φ = 8541280.

The previous prime is 21384421. The next prime is 21384449. The reversal of 21384430 is 3448312.

It is a junction number, because it is equal to n+sod(n) for n = 21384395 and 21384404.

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, 9075 + ... + 11185.

It is an arithmetic number, because the mean of its divisors is an integer number (2409264).

Almost surely, 2^21384430 is an apocalyptic number.

21384430 is a deficient number, since it is larger than the sum of its proper divisors (17163794).

21384430 is a wasteful number, since it uses less digits than its factorization.

21384430 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3131.

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 21384430 is about 4624.3302217727. The cubic root of 21384430 is about 277.5657610023.

The spelling of 21384430 in words is "twenty-one million, three hundred eighty-four thousand, four hundred thirty".