1265381878 has 8 divisors (see below), whose sum is σ = 1917640872. Its totient is φ = 626168256.

The previous prime is 1265381861. The next prime is 1265381881. The reversal of 1265381878 is 8781835621.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent 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, 3261100 + ... + 3261487.

It is an arithmetic number, because the mean of its divisors is an integer number (239705109).

Almost surely, 2^1265381878 is an apocalyptic number.

1265381878 is a deficient number, since it is larger than the sum of its proper divisors (652258994).

1265381878 is an equidigital number, since it uses as much as digits as its factorization.

1265381878 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6522686.

The product of its digits is 645120, while the sum is 49.

The square root of 1265381878 is about 35572.2065382512. The cubic root of 1265381878 is about 1081.6179105592.

The spelling of 1265381878 in words is "one billion, two hundred sixty-five million, three hundred eighty-one thousand, eight hundred seventy-eight".