21423120137 has 2 divisors, whose sum is σ = 21423120138. Its totient is φ = 21423120136.

The previous prime is 21423120113. The next prime is 21423120181. The reversal of 21423120137 is 73102132412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11986746256 + 9436373881 = 109484^2 + 97141^2 .

It is a cyclic number.

It is not a de Polignac number, because 21423120137 - 2⁶ = 21423120073 is a prime.

It is not a weakly prime, because it can be changed into another prime (21423120107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10711560068 + 10711560069.

It is an arithmetic number, because the mean of its divisors is an integer number (10711560069).

Almost surely, 2^21423120137 is an apocalyptic number.

It is an amenable number.

21423120137 is a deficient number, since it is larger than the sum of its proper divisors (1).

21423120137 is an equidigital number, since it uses as much as digits as its factorization.

21423120137 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2016, while the sum is 26.

Adding to 21423120137 its reverse (73102132412), we get a palindrome (94525252549).

The spelling of 21423120137 in words is "twenty-one billion, four hundred twenty-three million, one hundred twenty thousand, one hundred thirty-seven".