816778369 has 8 divisors (see below), whose sum is σ = 929771712. Its totient is φ = 710241840.

The previous prime is 816778357. The next prime is 816778387. The reversal of 816778369 is 963877618.

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

It is not a de Polignac number, because 816778369 - 2⁵ = 816778337 is a prime.

It is a super-2 number, since 2×816778369² = 1334253808132600322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (816778169) 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, 1613934 + ... + 1614439.

It is an arithmetic number, because the mean of its divisors is an integer number (116221464).

Almost surely, 2^816778369 is an apocalyptic number.

It is an amenable number.

816778369 is a deficient number, since it is larger than the sum of its proper divisors (112993343).

816778369 is a wasteful number, since it uses less digits than its factorization.

816778369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3228407.

The product of its digits is 3048192, while the sum is 55.

The square root of 816778369 is about 28579.3346493581. The cubic root of 816778369 is about 934.7627750904.

The spelling of 816778369 in words is "eight hundred sixteen million, seven hundred seventy-eight thousand, three hundred sixty-nine".