778261871 has 2 divisors, whose sum is σ = 778261872. Its totient is φ = 778261870.

The previous prime is 778261837. The next prime is 778261909. The reversal of 778261871 is 178162877.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 778261871 - 2²⁶ = 711153007 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 (778269871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 389130935 + 389130936.

It is an arithmetic number, because the mean of its divisors is an integer number (389130936).

Almost surely, 2^778261871 is an apocalyptic number.

778261871 is a deficient number, since it is larger than the sum of its proper divisors (1).

778261871 is an equidigital number, since it uses as much as digits as its factorization.

778261871 is an evil number, because the sum of its binary digits is even.

The product of its digits is 263424, while the sum is 47.

The square root of 778261871 is about 27897.3452321184. The cubic root of 778261871 is about 919.8321491985.

It can be divided in two parts, 77826 and 1871, that added together give a palindrome (79697).

The spelling of 778261871 in words is "seven hundred seventy-eight million, two hundred sixty-one thousand, eight hundred seventy-one".