812161378 has 12 divisors (see below), whose sum is σ = 1417138902. Its totient is φ = 348069120.

The previous prime is 812161369. The next prime is 812161379. The reversal of 812161378 is 873161218.

It can be written as a sum of positive squares in only one way, i.e., 812079009 + 82369 = 28497^2 + 287^2 .

It is a super-2 number, since 2×812161378² = 1319212207829717768, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (812161379) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4143583 + ... + 4143778.

Almost surely, 2^812161378 is an apocalyptic number.

812161378 is a deficient number, since it is larger than the sum of its proper divisors (604977524).

812161378 is a wasteful number, since it uses less digits than its factorization.

812161378 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8287377 (or 8287370 counting only the distinct ones).

The product of its digits is 16128, while the sum is 37.

The square root of 812161378 is about 28498.4451856588. The cubic root of 812161378 is about 932.9981393563.

The spelling of 812161378 in words is "eight hundred twelve million, one hundred sixty-one thousand, three hundred seventy-eight".