21552897 has 16 divisors (see below), whose sum is σ = 30536000. Its totient is φ = 13483584.

The previous prime is 21552893. The next prime is 21552911. The reversal of 21552897 is 79825512.

It is not a de Polignac number, because 21552897 - 2² = 21552893 is a prime.

It is a Duffinian number.

Its product of digits (50400) is a multiple of the sum of its prime divisors (3600).

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 (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4479 + ... + 7947.

It is an arithmetic number, because the mean of its divisors is an integer number (1908500).

Almost surely, 2^21552897 is an apocalyptic number.

It is an amenable number.

21552897 is a deficient number, since it is larger than the sum of its proper divisors (8983103).

21552897 is a wasteful number, since it uses less digits than its factorization.

21552897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3600.

The product of its digits is 50400, while the sum is 39.

The square root of 21552897 is about 4642.5097738185. The cubic root of 21552897 is about 278.2927449470.

The spelling of 21552897 in words is "twenty-one million, five hundred fifty-two thousand, eight hundred ninety-seven".