778197081 has 4 divisors (see below), whose sum is σ = 1037596112. Its totient is φ = 518798052.

The previous prime is 778197071. The next prime is 778197103. The reversal of 778197081 is 180791877.

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.

It is not a de Polignac number, because 778197081 - 2⁹ = 778196569 is a prime.

It is a super-2 number, since 2×778197081² = 1211181393753841122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 778197081.

It is not an unprimeable number, because it can be changed into a prime (778197071) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129699511 + ... + 129699516.

It is an arithmetic number, because the mean of its divisors is an integer number (259399028).

Almost surely, 2^778197081 is an apocalyptic number.

It is an amenable number.

778197081 is a deficient number, since it is larger than the sum of its proper divisors (259399031).

778197081 is a wasteful number, since it uses less digits than its factorization.

778197081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259399030.

The product of its (nonzero) digits is 197568, while the sum is 48.

The square root of 778197081 is about 27896.1839863448. The cubic root of 778197081 is about 919.8066232665.

The spelling of 778197081 in words is "seven hundred seventy-eight million, one hundred ninety-seven thousand, eighty-one".