21402748 has 12 divisors (see below), whose sum is σ = 38014312. Its totient is φ = 10541520.

The previous prime is 21402739. The next prime is 21402763. The reversal of 21402748 is 84720412.

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, 39663 + ... + 40198.

Almost surely, 2^21402748 is an apocalyptic number.

It is an amenable number.

21402748 is a deficient number, since it is larger than the sum of its proper divisors (16611564).

21402748 is a wasteful number, since it uses less digits than its factorization.

21402748 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 79932 (or 79930 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 28.

The square root of 21402748 is about 4626.3104089544. The cubic root of 21402748 is about 277.6449930809.

The spelling of 21402748 in words is "twenty-one million, four hundred two thousand, seven hundred forty-eight".