21187452 has 48 divisors (see below), whose sum is σ = 58084992. Its totient is φ = 5926080.

The previous prime is 21187417. The next prime is 21187469. The reversal of 21187452 is 25478112.

It is a Smith number, since the sum of its digits (30) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4458 + ... + 7889.

It is an arithmetic number, because the mean of its divisors is an integer number (1210104).

Almost surely, 2^21187452 is an apocalyptic number.

21187452 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

21187452 is an abundant number, since it is smaller than the sum of its proper divisors (36897540).

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

21187452 is a wasteful number, since it uses less digits than its factorization.

21187452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12378 (or 12376 counting only the distinct ones).

The product of its digits is 4480, while the sum is 30.

The square root of 21187452 is about 4602.9829458733. The cubic root of 21187452 is about 276.7108853373.

The spelling of 21187452 in words is "twenty-one million, one hundred eighty-seven thousand, four hundred fifty-two".