136640789 has 2 divisors, whose sum is σ = 136640790. Its totient is φ = 136640788.

The previous prime is 136640773. The next prime is 136640809. The reversal of 136640789 is 987046631.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 102616900 + 34023889 = 10130^2 + 5833^2 .

It is a cyclic number.

It is not a de Polignac number, because 136640789 - 2⁴ = 136640773 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (136640759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 68320394 + 68320395.

It is an arithmetic number, because the mean of its divisors is an integer number (68320395).

Almost surely, 2^136640789 is an apocalyptic number.

It is an amenable number.

136640789 is a deficient number, since it is larger than the sum of its proper divisors (1).

136640789 is an equidigital number, since it uses as much as digits as its factorization.

136640789 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 217728, while the sum is 44.

The square root of 136640789 is about 11689.3451056935. The cubic root of 136640789 is about 515.0627240032.

The spelling of 136640789 in words is "one hundred thirty-six million, six hundred forty thousand, seven hundred eighty-nine".