21828627605 has 4 divisors (see below), whose sum is σ = 26194353132. Its totient is φ = 17462902080.

The previous prime is 21828627581. The next prime is 21828627607. The reversal of 21828627605 is 50672682812.

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

It can be written as a sum of positive squares in 2 ways, for example, as 15650510404 + 6178117201 = 125102^2 + 78601^2 .

It is not a de Polignac number, because 21828627605 - 2¹⁴ = 21828611221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21828627605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21828627607) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2182862756 + ... + 2182862765.

It is an arithmetic number, because the mean of its divisors is an integer number (6548588283).

Almost surely, 2^21828627605 is an apocalyptic number.

It is an amenable number.

21828627605 is a deficient number, since it is larger than the sum of its proper divisors (4365725527).

21828627605 is an equidigital number, since it uses as much as digits as its factorization.

21828627605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4365725526.

The product of its (nonzero) digits is 645120, while the sum is 47.

The spelling of 21828627605 in words is "twenty-one billion, eight hundred twenty-eight million, six hundred twenty-seven thousand, six hundred five".