21269568 has 56 divisors (see below), whose sum is σ = 57497472. Its totient is φ = 6936064.

The previous prime is 21269551. The next prime is 21269593. The reversal of 21269568 is 86596212.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7846 + ... + 10202.

Almost surely, 2^21269568 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 21269568, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28748736).

21269568 is an abundant number, since it is smaller than the sum of its proper divisors (36227904).

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

21269568 is a wasteful number, since it uses less digits than its factorization.

21269568 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2419 (or 2409 counting only the distinct ones).

The product of its digits is 51840, while the sum is 39.

The square root of 21269568 is about 4611.8941878582. The cubic root of 21269568 is about 277.0679063879.

The spelling of 21269568 in words is "twenty-one million, two hundred sixty-nine thousand, five hundred sixty-eight".