21724334 has 16 divisors (see below), whose sum is σ = 36320400. Its totient is φ = 9684864.

The previous prime is 21724333. The next prime is 21724361. The reversal of 21724334 is 43342712.

21724334 = 81² + 82² + ... + 403².

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21724333) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16169 + ... + 17460.

It is an arithmetic number, because the mean of its divisors is an integer number (2270025).

Almost surely, 2^21724334 is an apocalyptic number.

21724334 is a deficient number, since it is larger than the sum of its proper divisors (14596066).

21724334 is a wasteful number, since it uses less digits than its factorization.

21724334 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33667.

The product of its digits is 4032, while the sum is 26.

The square root of 21724334 is about 4660.9370302548. The cubic root of 21724334 is about 279.0286666074.

The spelling of 21724334 in words is "twenty-one million, seven hundred twenty-four thousand, three hundred thirty-four".