21704740 has 24 divisors (see below), whose sum is σ = 45888192. Its totient is φ = 8623200.

The previous prime is 21704737. The next prime is 21704791. The reversal of 21704740 is 4740712.

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, 574 + ... + 6613.

It is an arithmetic number, because the mean of its divisors is an integer number (1912008).

Almost surely, 2^21704740 is an apocalyptic number.

21704740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21704740 is an abundant number, since it is smaller than the sum of its proper divisors (24183452).

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

21704740 is a wasteful number, since it uses less digits than its factorization.

21704740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7347 (or 7345 counting only the distinct ones).

The product of its (nonzero) digits is 1568, while the sum is 25.

The square root of 21704740 is about 4658.8346182280. The cubic root of 21704740 is about 278.9447525315.

The spelling of 21704740 in words is "twenty-one million, seven hundred four thousand, seven hundred forty".