21555152 has 20 divisors (see below), whose sum is σ = 41842560. Its totient is φ = 10757088.

The previous prime is 21555113. The next prime is 21555179. The reversal of 21555152 is 25155512.

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, 10913 + ... + 12735.

It is an arithmetic number, because the mean of its divisors is an integer number (2092128).

Almost surely, 2^21555152 is an apocalyptic number.

It is an amenable number.

21555152 is a deficient number, since it is larger than the sum of its proper divisors (20287408).

21555152 is a wasteful number, since it uses less digits than its factorization.

21555152 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2570 (or 2564 counting only the distinct ones).

The product of its digits is 2500, while the sum is 26.

The square root of 21555152 is about 4642.7526317908. The cubic root of 21555152 is about 278.3024501891.

The spelling of 21555152 in words is "twenty-one million, five hundred fifty-five thousand, one hundred fifty-two".