1243695137 has 2 divisors, whose sum is σ = 1243695138. Its totient is φ = 1243695136.

The previous prime is 1243695127. The next prime is 1243695199. The reversal of 1243695137 is 7315963421.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 664041361 + 579653776 = 25769^2 + 24076^2 .

It is a cyclic number.

It is not a de Polignac number, because 1243695137 - 2¹⁶ = 1243629601 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1243695094 and 1243695103.

It is not a weakly prime, because it can be changed into another prime (1243695127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 621847568 + 621847569.

It is an arithmetic number, because the mean of its divisors is an integer number (621847569).

Almost surely, 2^1243695137 is an apocalyptic number.

It is an amenable number.

1243695137 is a deficient number, since it is larger than the sum of its proper divisors (1).

1243695137 is an equidigital number, since it uses as much as digits as its factorization.

1243695137 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 136080, while the sum is 41.

The square root of 1243695137 is about 35266.0621135958. The cubic root of 1243695137 is about 1075.4031693456.

The spelling of 1243695137 in words is "one billion, two hundred forty-three million, six hundred ninety-five thousand, one hundred thirty-seven".