21055752 has 24 divisors (see below), whose sum is σ = 57026190. Its totient is φ = 7018560.

The previous prime is 21055739. The next prime is 21055759. The reversal of 21055752 is 25755012.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 11655396 + 9400356 = 3414^2 + 3066^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (21055759) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 146149 + ... + 146292.

Almost surely, 2^21055752 is an apocalyptic number.

It is an amenable number.

21055752 is an abundant number, since it is smaller than the sum of its proper divisors (35970438).

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

21055752 is a wasteful number, since it uses less digits than its factorization.

21055752 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 292453 (or 292446 counting only the distinct ones).

The product of its (nonzero) digits is 3500, while the sum is 27.

The square root of 21055752 is about 4588.6547048127. The cubic root of 21055752 is about 276.1363535455.

The spelling of 21055752 in words is "twenty-one million, fifty-five thousand, seven hundred fifty-two".