115640257 has 4 divisors (see below), whose sum is σ = 118100736. Its totient is φ = 113179780.

The previous prime is 115640243. The next prime is 115640267. The reversal of 115640257 is 752046511.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 752046511 = 73 ⋅10302007.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-115640257 is a prime.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (115640267) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1230169 + ... + 1230262.

It is an arithmetic number, because the mean of its divisors is an integer number (29525184).

Almost surely, 2^115640257 is an apocalyptic number.

It is an amenable number.

115640257 is a deficient number, since it is larger than the sum of its proper divisors (2460479).

115640257 is an equidigital number, since it uses as much as digits as its factorization.

115640257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2460478.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 115640257 is about 10753.6159964916. The cubic root of 115640257 is about 487.1952170735.

Adding to 115640257 its reverse (752046511), we get a palindrome (867686768).

The spelling of 115640257 in words is "one hundred fifteen million, six hundred forty thousand, two hundred fifty-seven".