21584742 has 16 divisors (see below), whose sum is σ = 44562432. Its totient is φ = 6962760.

The previous prime is 21584723. The next prime is 21584743. The reversal of 21584742 is 24748512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21584743) by changing a digit.

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, 57838 + ... + 58209.

It is an arithmetic number, because the mean of its divisors is an integer number (2785152).

Almost surely, 2^21584742 is an apocalyptic number.

21584742 is an abundant number, since it is smaller than the sum of its proper divisors (22977690).

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

21584742 is a wasteful number, since it uses less digits than its factorization.

21584742 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116083.

The product of its digits is 17920, while the sum is 33.

The square root of 21584742 is about 4645.9382260207. The cubic root of 21584742 is about 278.4297392346.

The spelling of 21584742 in words is "twenty-one million, five hundred eighty-four thousand, seven hundred forty-two".