21253208 has 16 divisors (see below), whose sum is σ = 39913560. Its totient is φ = 10609600.

The previous prime is 21253189. The next prime is 21253217. The reversal of 21253208 is 80235212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4343 + ... + 7833.

Almost surely, 2^21253208 is an apocalyptic number.

It is an amenable number.

21253208 is a deficient number, since it is larger than the sum of its proper divisors (18660352).

21253208 is a wasteful number, since it uses less digits than its factorization.

21253208 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4258 (or 4254 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 21253208 is about 4610.1201719695. The cubic root of 21253208 is about 276.9968503510.

The spelling of 21253208 in words is "twenty-one million, two hundred fifty-three thousand, two hundred eight".