21775552 has 28 divisors (see below), whose sum is σ = 43607736. Its totient is φ = 10787840.

The previous prime is 21775531. The next prime is 21775571. The reversal of 21775552 is 25557712.

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, 5727 + ... + 8737.

Almost surely, 2^21775552 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 21775552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21803868).

21775552 is an abundant number, since it is smaller than the sum of its proper divisors (21832184).

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

21775552 is a wasteful number, since it uses less digits than its factorization.

21775552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3136 (or 3126 counting only the distinct ones).

The product of its digits is 24500, while the sum is 34.

The square root of 21775552 is about 4666.4281843826. The cubic root of 21775552 is about 279.2477768722.

The spelling of 21775552 in words is "twenty-one million, seven hundred seventy-five thousand, five hundred fifty-two".