21665334 has 16 divisors (see below), whose sum is σ = 43524288. Its totient is φ = 7189512.

The previous prime is 21665279. The next prime is 21665341. The reversal of 21665334 is 43356612.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6592 + ... + 9315.

It is an arithmetic number, because the mean of its divisors is an integer number (2720268).

Almost surely, 2^21665334 is an apocalyptic number.

21665334 is an abundant number, since it is smaller than the sum of its proper divisors (21858954).

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

21665334 is a wasteful number, since it uses less digits than its factorization.

21665334 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16139.

The product of its digits is 12960, while the sum is 30.

The square root of 21665334 is about 4654.6035276917. The cubic root of 21665334 is about 278.7758377251.

The spelling of 21665334 in words is "twenty-one million, six hundred sixty-five thousand, three hundred thirty-four".