775978261 has 4 divisors (see below), whose sum is σ = 776034592. Its totient is φ = 775921932.

The previous prime is 775978213. The next prime is 775978283. The reversal of 775978261 is 162879577.

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 a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 775978261 - 2²⁷ = 641760533 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 775978199 and 775978208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (775976261) 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, 7846 + ... + 40168.

It is an arithmetic number, because the mean of its divisors is an integer number (194008648).

Almost surely, 2^775978261 is an apocalyptic number.

It is an amenable number.

775978261 is a deficient number, since it is larger than the sum of its proper divisors (56331).

775978261 is a wasteful number, since it uses less digits than its factorization.

775978261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56330.

The product of its digits is 1481760, while the sum is 52.

The square root of 775978261 is about 27856.3863593252. The cubic root of 775978261 is about 918.9315972442.

It can be divided in two parts, 77597 and 8261, that added together give a palindrome (85858).

The spelling of 775978261 in words is "seven hundred seventy-five million, nine hundred seventy-eight thousand, two hundred sixty-one".