21552895 has 48 divisors (see below), whose sum is σ = 33209568. Its totient is φ = 13305600.

The previous prime is 21552893. The next prime is 21552911. The reversal of 21552895 is 59825512.

21552895 is a nontrivial binomial coefficient, being equal to C(6566, 2).

It is not a de Polignac number, because 21552895 - 2¹ = 21552893 is a prime.

Its product of digits (36000) is a multiple of the sum of its prime factors (200).

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21552893) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 213345 + ... + 213445.

It is an arithmetic number, because the mean of its divisors is an integer number (691866).

Almost surely, 2^21552895 is an apocalyptic number.

21552895 is the 6565-th triangular number and also the 3283-rd hexagonal number.

21552895 is the 2189-th centered nonagonal number.

21552895 is a deficient number, since it is larger than the sum of its proper divisors (11656673).

21552895 is a wasteful number, since it uses less digits than its factorization.

21552895 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200 (or 193 counting only the distinct ones).

The product of its digits is 36000, while the sum is 37.

The square root of 21552895 is about 4642.5095584177. The cubic root of 21552895 is about 278.2927363389.

It can be divided in two parts, 2155 and 2895, that added together give a triangular number (5050 = T₁₀₀).

The spelling of 21552895 in words is "twenty-one million, five hundred fifty-two thousand, eight hundred ninety-five".