21279704 has 8 divisors (see below), whose sum is σ = 39899460. Its totient is φ = 10639848.

The previous prime is 21279703. The next prime is 21279721. The reversal of 21279704 is 40797212.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21279701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1329974 + ... + 1329989.

Almost surely, 2^21279704 is an apocalyptic number.

It is an amenable number.

21279704 is a deficient number, since it is larger than the sum of its proper divisors (18619756).

21279704 is a wasteful number, since it uses less digits than its factorization.

21279704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2659969 (or 2659965 counting only the distinct ones).

The product of its (nonzero) digits is 7056, while the sum is 32.

The square root of 21279704 is about 4612.9929546879. The cubic root of 21279704 is about 277.1119115805. Note that the first 3 decimals are identical.

The spelling of 21279704 in words is "twenty-one million, two hundred seventy-nine thousand, seven hundred four".