778880861 has 8 divisors (see below), whose sum is σ = 853076448. Its totient is φ = 705250000.

The previous prime is 778880849. The next prime is 778880923. The reversal of 778880861 is 168088877.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 778880861 - 2¹⁴ = 778864477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (778880161) 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, 138290 + ... + 143811.

It is an arithmetic number, because the mean of its divisors is an integer number (106634556).

Almost surely, 2^778880861 is an apocalyptic number.

It is an amenable number.

778880861 is a deficient number, since it is larger than the sum of its proper divisors (74195587).

778880861 is a wasteful number, since it uses less digits than its factorization.

778880861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 282363.

The product of its (nonzero) digits is 1204224, while the sum is 53.

The square root of 778880861 is about 27908.4370934669. The cubic root of 778880861 is about 920.0759471802.

The spelling of 778880861 in words is "seven hundred seventy-eight million, eight hundred eighty thousand, eight hundred sixty-one".