21125288 has 16 divisors (see below), whose sum is σ = 41940180. Its totient is φ = 9941248.

The previous prime is 21125267. The next prime is 21125303. The reversal of 21125288 is 88252112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 19377604 + 1747684 = 4402^2 + 1322^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21125288.

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, 77531 + ... + 77802.

Almost surely, 2^21125288 is an apocalyptic number.

It is an amenable number.

21125288 is a deficient number, since it is larger than the sum of its proper divisors (20814892).

21125288 is a wasteful number, since it uses less digits than its factorization.

21125288 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 155356 (or 155352 counting only the distinct ones).

The product of its digits is 2560, while the sum is 29.

The square root of 21125288 is about 4596.2254078755. The cubic root of 21125288 is about 276.4399969206.

The spelling of 21125288 in words is "twenty-one million, one hundred twenty-five thousand, two hundred eighty-eight".