21269888 has 32 divisors (see below), whose sum is σ = 42797160. Its totient is φ = 10528768.

The previous prime is 21269879. The next prime is 21269903. The reversal of 21269888 is 88896212.

It is a tau number, because it is divible by the number of its divisors (32).

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, 12920 + ... + 14472.

Almost surely, 2^21269888 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21269888, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21398580).

21269888 is an abundant number, since it is smaller than the sum of its proper divisors (21527272).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21269888 is a wasteful number, since it uses less digits than its factorization.

21269888 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1674 (or 1662 counting only the distinct ones).

The product of its digits is 110592, while the sum is 44.

The square root of 21269888 is about 4611.9288806312. The cubic root of 21269888 is about 277.0692958737.

The spelling of 21269888 in words is "twenty-one million, two hundred sixty-nine thousand, eight hundred eighty-eight".