21384742 has 32 divisors (see below), whose sum is σ = 35458560. Its totient is φ = 9630720.

The previous prime is 21384731. The next prime is 21384743. The reversal of 21384742 is 24748312.

Its product of digits (10752) is a multiple of the sum of its prime divisors (336).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21384743) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 111867 + ... + 112057.

It is an arithmetic number, because the mean of its divisors is an integer number (1108080).

Almost surely, 2^21384742 is an apocalyptic number.

21384742 is a deficient number, since it is larger than the sum of its proper divisors (14073818).

21384742 is a wasteful number, since it uses less digits than its factorization.

21384742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 336.

The product of its digits is 10752, while the sum is 31.

The square root of 21384742 is about 4624.3639562647. The cubic root of 21384742 is about 277.5671108956.

The spelling of 21384742 in words is "twenty-one million, three hundred eighty-four thousand, seven hundred forty-two".