21972000005 has 4 divisors (see below), whose sum is σ = 26366400012. Its totient is φ = 17577600000.

The previous prime is 21971999977. The next prime is 21972000041. The reversal of 21972000005 is 50000027912.

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 14853028129 + 7118971876 = 121873^2 + 84374^2 .

It is not a de Polignac number, because 21972000005 - 2²⁴ = 21955222789 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2197199996 + ... + 2197200005.

It is an arithmetic number, because the mean of its divisors is an integer number (6591600003).

Almost surely, 2^21972000005 is an apocalyptic number.

It is an amenable number.

21972000005 is a deficient number, since it is larger than the sum of its proper divisors (4394400007).

21972000005 is an equidigital number, since it uses as much as digits as its factorization.

21972000005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4394400006.

The product of its (nonzero) digits is 1260, while the sum is 26.

Adding to 21972000005 its reverse (50000027912), we get a palindrome (71972027917).

The spelling of 21972000005 in words is "twenty-one billion, nine hundred seventy-two million, five", and thus it is an aban number.