21708248 has 8 divisors (see below), whose sum is σ = 40702980. Its totient is φ = 10854120.

The previous prime is 21708223. The next prime is 21708263. The reversal of 21708248 is 84280712.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1356758 + ... + 1356773.

Almost surely, 2^21708248 is an apocalyptic number.

It is an amenable number.

21708248 is a deficient number, since it is larger than the sum of its proper divisors (18994732).

21708248 is a wasteful number, since it uses less digits than its factorization.

21708248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2713537 (or 2713533 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 21708248 is about 4659.2110920198. The cubic root of 21708248 is about 278.9597797479.

The spelling of 21708248 in words is "twenty-one million, seven hundred eight thousand, two hundred forty-eight".