21000248 has 16 divisors (see below), whose sum is σ = 39745080. Its totient is φ = 10401568.

The previous prime is 21000233. The next prime is 21000251. The reversal of 21000248 is 84200012.

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, 11411 + ... + 13122.

Almost surely, 2^21000248 is an apocalyptic number.

It is an amenable number.

21000248 is a deficient number, since it is larger than the sum of its proper divisors (18744832).

21000248 is a wasteful number, since it uses less digits than its factorization.

21000248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24646 (or 24642 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 17.

The square root of 21000248 is about 4582.6027538943. The cubic root of 21000248 is about 275.8935036865.

The spelling of 21000248 in words is "twenty-one million, two hundred forty-eight", and thus it is an aban number.