21556454 has 8 divisors (see below), whose sum is σ = 33449760. Its totient is φ = 10406536.

The previous prime is 21556441. The next prime is 21556477. The reversal of 21556454 is 45465512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21556454.

It is a congruent number.

It is an unprimeable number.

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 3 ways as a sum of consecutive naturals, for example, 185774 + ... + 185889.

It is an arithmetic number, because the mean of its divisors is an integer number (4181220).

Almost surely, 2^21556454 is an apocalyptic number.

21556454 is a deficient number, since it is larger than the sum of its proper divisors (11893306).

21556454 is a wasteful number, since it uses less digits than its factorization.

21556454 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 371694.

The product of its digits is 24000, while the sum is 32.

The square root of 21556454 is about 4642.8928482144. The cubic root of 21556454 is about 278.3080535285.

The spelling of 21556454 in words is "twenty-one million, five hundred fifty-six thousand, four hundred fifty-four".