816677780 has 12 divisors (see below), whose sum is σ = 1715023380. Its totient is φ = 326671104.

The previous prime is 816677731. The next prime is 816677783. The reversal of 816677780 is 87776618.

It can be written as a sum of positive squares in 2 ways, for example, as 306460036 + 510217744 = 17506^2 + 22588^2 .

It is a hoax number, since the sum of its digits (50) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816677783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 20416925 + ... + 20416964.

It is an arithmetic number, because the mean of its divisors is an integer number (142918615).

Almost surely, 2^816677780 is an apocalyptic number.

It is an amenable number.

816677780 is an abundant number, since it is smaller than the sum of its proper divisors (898345600).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

816677780 is a wasteful number, since it uses less digits than its factorization.

816677780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40833898 (or 40833896 counting only the distinct ones).

The product of its (nonzero) digits is 790272, while the sum is 50.

The square root of 816677780 is about 28577.5747746375. The cubic root of 816677780 is about 934.7244004563.

The spelling of 816677780 in words is "eight hundred sixteen million, six hundred seventy-seven thousand, seven hundred eighty".