816791788076634 has 40 divisors (see below), whose sum is σ = 1836465116339700. Its totient is φ = 271334700915264.

The previous prime is 816791788076567. The next prime is 816791788076639. The reversal of 816791788076634 is 436670887197618.

It can be written as a sum of positive squares in 2 ways, for example, as 804945133118025 + 11846654958609 = 28371555^2 + 3441897^2 .

It is a Smith number, since the sum of its digits (81) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (81).

It is not an unprimeable number, because it can be changed into a prime (816791788076639) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 8603919459 + ... + 8604014390.

Almost surely, 2^{816791788076634} is an apocalyptic number.

816791788076634 is an abundant number, since it is smaller than the sum of its proper divisors (1019673328263066).

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

816791788076634 is a wasteful number, since it uses less digits than its factorization.

816791788076634 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17207934156 (or 17207934147 counting only the distinct ones).

The product of its (nonzero) digits is 4096770048, while the sum is 81.

The spelling of 816791788076634 in words is "eight hundred sixteen trillion, seven hundred ninety-one billion, seven hundred eighty-eight million, seventy-six thousand, six hundred thirty-four".