21552456 has 16 divisors (see below), whose sum is σ = 53881200. Its totient is φ = 7184144.

The previous prime is 21552451. The next prime is 21552457. The reversal of 21552456 is 65425512.

It is not an unprimeable number, because it can be changed into a prime (21552451) 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 3 ways as a sum of consecutive naturals, for example, 448986 + ... + 449033.

It is an arithmetic number, because the mean of its divisors is an integer number (3367575).

Almost surely, 2^21552456 is an apocalyptic number.

It is an amenable number.

21552456 is an abundant number, since it is smaller than the sum of its proper divisors (32328744).

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

21552456 is a wasteful number, since it uses less digits than its factorization.

21552456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 898028 (or 898024 counting only the distinct ones).

The product of its digits is 12000, while the sum is 30.

The square root of 21552456 is about 4642.4622777143. The cubic root of 21552456 is about 278.2908468582.

Adding to 21552456 its reverse (65425512), we get a palindrome (86977968).

The spelling of 21552456 in words is "twenty-one million, five hundred fifty-two thousand, four hundred fifty-six".