778197561 has 8 divisors (see below), whose sum is σ = 1038049344. Its totient is φ = 518572080.

The previous prime is 778197533. The next prime is 778197583. The reversal of 778197561 is 165791877.

778197561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 778197561 - 2⁵ = 778197529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (778197361) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48381 + ... + 62426.

It is an arithmetic number, because the mean of its divisors is an integer number (129756168).

Almost surely, 2^778197561 is an apocalyptic number.

It is an amenable number.

778197561 is a deficient number, since it is larger than the sum of its proper divisors (259851783).

778197561 is a wasteful number, since it uses less digits than its factorization.

778197561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113151.

The product of its digits is 740880, while the sum is 51.

The square root of 778197561 is about 27896.1925896707. The cubic root of 778197561 is about 919.8068123818.

The spelling of 778197561 in words is "seven hundred seventy-eight million, one hundred ninety-seven thousand, five hundred sixty-one".