815712137 has 2 divisors, whose sum is σ = 815712138. Its totient is φ = 815712136.

The previous prime is 815712061. The next prime is 815712143. The reversal of 815712137 is 731217518.

It is a happy number.

815712137 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 481407481 + 334304656 = 21941^2 + 18284^2 .

It is a cyclic number.

It is not a de Polignac number, because 815712137 - 2⁸ = 815711881 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 815712097 and 815712106.

It is not a weakly prime, because it can be changed into another prime (815712197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 407856068 + 407856069.

It is an arithmetic number, because the mean of its divisors is an integer number (407856069).

Almost surely, 2^815712137 is an apocalyptic number.

It is an amenable number.

815712137 is a deficient number, since it is larger than the sum of its proper divisors (1).

815712137 is an equidigital number, since it uses as much as digits as its factorization.

815712137 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11760, while the sum is 35.

The square root of 815712137 is about 28560.6746593984. The cubic root of 815712137 is about 934.3558478970.

The spelling of 815712137 in words is "eight hundred fifteen million, seven hundred twelve thousand, one hundred thirty-seven".