21703906 has 32 divisors (see below), whose sum is σ = 39333888. Its totient is φ = 8784720.

The previous prime is 21703897. The next prime is 21703967. The reversal of 21703906 is 60930712.

21703906 is a modest number, since divided by 3906 gives 2170 as remainder.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18081 + ... + 19243.

It is an arithmetic number, because the mean of its divisors is an integer number (1229184).

Almost surely, 2^21703906 is an apocalyptic number.

21703906 is a deficient number, since it is larger than the sum of its proper divisors (17629982).

21703906 is a wasteful number, since it uses less digits than its factorization.

21703906 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1246.

The product of its (nonzero) digits is 2268, while the sum is 28.

The square root of 21703906 is about 4658.7451100055. The cubic root of 21703906 is about 278.9411796882.

The spelling of 21703906 in words is "twenty-one million, seven hundred three thousand, nine hundred six".