21804291055 has 4 divisors (see below), whose sum is σ = 26165149272. Its totient is φ = 17443432840.

The previous prime is 21804291053. The next prime is 21804291077. The reversal of 21804291055 is 55019240812.

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

It is not a de Polignac number, because 21804291055 - 2¹ = 21804291053 is a prime.

It is a super-2 number, since 2×21804291055² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21804291053) 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, 2180429101 + ... + 2180429110.

It is an arithmetic number, because the mean of its divisors is an integer number (6541287318).

Almost surely, 2^21804291055 is an apocalyptic number.

21804291055 is a deficient number, since it is larger than the sum of its proper divisors (4360858217).

21804291055 is an equidigital number, since it uses as much as digits as its factorization.

21804291055 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4360858216.

The product of its (nonzero) digits is 28800, while the sum is 37.

The spelling of 21804291055 in words is "twenty-one billion, eight hundred four million, two hundred ninety-one thousand, fifty-five".