21200112137 has 2 divisors, whose sum is σ = 21200112138. Its totient is φ = 21200112136.

The previous prime is 21200112133. The next prime is 21200112209. The reversal of 21200112137 is 73121100212.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20276620816 + 923491321 = 142396^2 + 30389^2 .

It is a cyclic number.

It is not a de Polignac number, because 21200112137 - 2² = 21200112133 is a prime.

It is not a weakly prime, because it can be changed into another prime (21200112133) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600056068 + 10600056069.

It is an arithmetic number, because the mean of its divisors is an integer number (10600056069).

Almost surely, 2^21200112137 is an apocalyptic number.

It is an amenable number.

21200112137 is a deficient number, since it is larger than the sum of its proper divisors (1).

21200112137 is an equidigital number, since it uses as much as digits as its factorization.

21200112137 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 168, while the sum is 20.

Adding to 21200112137 its reverse (73121100212), we get a palindrome (94321212349).

The spelling of 21200112137 in words is "twenty-one billion, two hundred million, one hundred twelve thousand, one hundred thirty-seven".