21749344 has 24 divisors (see below), whose sum is σ = 43733088. Its totient is φ = 10642560.

The previous prime is 21749323. The next prime is 21749353. The reversal of 21749344 is 44394712.

It is a happy number.

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 3 ways as a sum of consecutive naturals, for example, 5727 + ... + 8734.

It is an arithmetic number, because the mean of its divisors is an integer number (1822212).

Almost surely, 2^21749344 is an apocalyptic number.

It is an amenable number.

21749344 is an abundant number, since it is smaller than the sum of its proper divisors (21983744).

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

21749344 is a wasteful number, since it uses less digits than its factorization.

21749344 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14518 (or 14510 counting only the distinct ones).

The product of its digits is 24192, while the sum is 34.

The square root of 21749344 is about 4663.6191954318. The cubic root of 21749344 is about 279.1357021967.

The spelling of 21749344 in words is "twenty-one million, seven hundred forty-nine thousand, three hundred forty-four".