778564893 has 4 divisors (see below), whose sum is σ = 1038086528. Its totient is φ = 519043260.

The previous prime is 778564883. The next prime is 778564901. The reversal of 778564893 is 398465877.

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, and also an emirpimes, since its reverse is a distinct semiprime: 398465877 = 3 ⋅132821959.

It is not a de Polignac number, because 778564893 - 2¹⁶ = 778499357 is a prime.

It is a super-2 number, since 2×778564893² = 1212326585224202898, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (778564883) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 129760813 + ... + 129760818.

It is an arithmetic number, because the mean of its divisors is an integer number (259521632).

Almost surely, 2^778564893 is an apocalyptic number.

It is an amenable number.

778564893 is a deficient number, since it is larger than the sum of its proper divisors (259521635).

778564893 is a wasteful number, since it uses less digits than its factorization.

778564893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 259521634.

The product of its digits is 10160640, while the sum is 57.

The square root of 778564893 is about 27902.7757221392. The cubic root of 778564893 is about 919.9515148519.

The spelling of 778564893 in words is "seven hundred seventy-eight million, five hundred sixty-four thousand, eight hundred ninety-three".