21625652705 has 4 divisors (see below), whose sum is σ = 25950783252. Its totient is φ = 17300522160.

The previous prime is 21625652677. The next prime is 21625652753. The reversal of 21625652705 is 50725652612.

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 8864787409 + 12760865296 = 94153^2 + 112964^2 .

It is not a de Polignac number, because 21625652705 - 2¹⁴ = 21625636321 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2162565266 + ... + 2162565275.

It is an arithmetic number, because the mean of its divisors is an integer number (6487695813).

Almost surely, 2^21625652705 is an apocalyptic number.

It is an amenable number.

21625652705 is a deficient number, since it is larger than the sum of its proper divisors (4325130547).

21625652705 is an equidigital number, since it uses as much as digits as its factorization.

21625652705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4325130546.

The product of its (nonzero) digits is 252000, while the sum is 41.

The spelling of 21625652705 in words is "twenty-one billion, six hundred twenty-five million, six hundred fifty-two thousand, seven hundred five".