21854244551 has 4 divisors (see below), whose sum is σ = 21859564704. Its totient is φ = 21848924400.

The previous prime is 21854244527. The next prime is 21854244571. The reversal of 21854244551 is 15544245812.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21854244551 - 2¹⁴ = 21854228167 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21854244499 and 21854244508.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21854244571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2653910 + ... + 2662131.

It is an arithmetic number, because the mean of its divisors is an integer number (5464891176).

Almost surely, 2^21854244551 is an apocalyptic number.

21854244551 is a deficient number, since it is larger than the sum of its proper divisors (5320153).

21854244551 is an equidigital number, since it uses as much as digits as its factorization.

21854244551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5320152.

The product of its digits is 256000, while the sum is 41.

The spelling of 21854244551 in words is "twenty-one billion, eight hundred fifty-four million, two hundred forty-four thousand, five hundred fifty-one".