21552289 has 16 divisors (see below), whose sum is σ = 25018560. Its totient is φ = 18360000.

The previous prime is 21552283. The next prime is 21552317. The reversal of 21552289 is 98225512.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21552289 - 2⁵ = 21552257 is a prime.

It is a super-2 number, since 2×21552289² = 929002322279042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21552283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20599 + ... + 21619.

It is an arithmetic number, because the mean of its divisors is an integer number (1563660).

Almost surely, 2^21552289 is an apocalyptic number.

It is an amenable number.

21552289 is a deficient number, since it is larger than the sum of its proper divisors (3466271).

21552289 is a wasteful number, since it uses less digits than its factorization.

21552289 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1152.

The product of its digits is 14400, while the sum is 34.

The square root of 21552289 is about 4642.4442915344. Note that the first 3 decimals coincide. The cubic root of 21552289 is about 278.2901280740.

It can be divided in two parts, 2155 and 2289, that added together give a palindrome (4444).

The spelling of 21552289 in words is "twenty-one million, five hundred fifty-two thousand, two hundred eighty-nine".