1368781915 has 4 divisors (see below), whose sum is σ = 1642538304. Its totient is φ = 1095025528.

The previous prime is 1368781889. The next prime is 1368781961. The reversal of 1368781915 is 5191878631.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5191878631 = 977 ⋅5314103.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1368781915 is a prime.

It is a Smith number, since the sum of its digits (49) 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 an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 136878187 + ... + 136878196.

It is an arithmetic number, because the mean of its divisors is an integer number (410634576).

Almost surely, 2^1368781915 is an apocalyptic number.

1368781915 is a deficient number, since it is larger than the sum of its proper divisors (273756389).

1368781915 is an equidigital number, since it uses as much as digits as its factorization.

1368781915 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 273756388.

The product of its digits is 362880, while the sum is 49.

The square root of 1368781915 is about 36997.0527880262. The cubic root of 1368781915 is about 1110.3112821752.

The spelling of 1368781915 in words is "one billion, three hundred sixty-eight million, seven hundred eighty-one thousand, nine hundred fifteen".