1540115729 has 2 divisors, whose sum is σ = 1540115730. Its totient is φ = 1540115728.

The previous prime is 1540115683. The next prime is 1540115747. The reversal of 1540115729 is 9275110451.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1312105729 + 228010000 = 36223^2 + 15100^2 .

It is a cyclic number.

It is not a de Polignac number, because 1540115729 - 2²⁴ = 1523338513 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (1540115429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 770057864 + 770057865.

It is an arithmetic number, because the mean of its divisors is an integer number (770057865).

Almost surely, 2^1540115729 is an apocalyptic number.

It is an amenable number.

1540115729 is a deficient number, since it is larger than the sum of its proper divisors (1).

1540115729 is an equidigital number, since it uses as much as digits as its factorization.

1540115729 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12600, while the sum is 35.

The square root of 1540115729 is about 39244.3082369915. The cubic root of 1540115729 is about 1154.8292768158.

The spelling of 1540115729 in words is "one billion, five hundred forty million, one hundred fifteen thousand, seven hundred twenty-nine".