21455534 has 16 divisors (see below), whose sum is σ = 34369920. Its totient is φ = 10022880.

The previous prime is 21455521. The next prime is 21455537. The reversal of 21455534 is 43555412.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21455497 and 21455506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21455537) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 4169 + ... + 7764.

It is an arithmetic number, because the mean of its divisors is an integer number (2148120).

Almost surely, 2^21455534 is an apocalyptic number.

21455534 is a deficient number, since it is larger than the sum of its proper divisors (12914386).

21455534 is a wasteful number, since it uses less digits than its factorization.

21455534 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11995.

The product of its digits is 12000, while the sum is 29.

The square root of 21455534 is about 4632.0118739053. The cubic root of 21455534 is about 277.8730593785.

The spelling of 21455534 in words is "twenty-one million, four hundred fifty-five thousand, five hundred thirty-four".