816121193 has 16 divisors (see below), whose sum is σ = 916297920. Its totient is φ = 722336256.

The previous prime is 816121157. The next prime is 816121199. The reversal of 816121193 is 391121618.

It is not a de Polignac number, because 816121193 - 2⁶ = 816121129 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (816121199) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 35030 + ... + 53472.

It is an arithmetic number, because the mean of its divisors is an integer number (57268620).

Almost surely, 2^816121193 is an apocalyptic number.

It is an amenable number.

816121193 is a deficient number, since it is larger than the sum of its proper divisors (100176727).

816121193 is a wasteful number, since it uses less digits than its factorization.

816121193 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18616.

The product of its digits is 2592, while the sum is 32.

The square root of 816121193 is about 28567.8349372157. The cubic root of 816121193 is about 934.5120059247.

The spelling of 816121193 in words is "eight hundred sixteen million, one hundred twenty-one thousand, one hundred ninety-three".