816131640029 has 4 divisors (see below), whose sum is σ = 816195308700. Its totient is φ = 816067971360.

The previous prime is 816131639929. The next prime is 816131640053. The reversal of 816131640029 is 920046131618.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 194238525625 + 621893114404 = 440725^2 + 788602^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-816131640029 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (816131640089) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 31815104 + ... + 31840745.

It is an arithmetic number, because the mean of its divisors is an integer number (204048827175).

Almost surely, 2^816131640029 is an apocalyptic number.

It is an amenable number.

816131640029 is a deficient number, since it is larger than the sum of its proper divisors (63668671).

816131640029 is a wasteful number, since it uses less digits than its factorization.

816131640029 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 63668670.

The product of its (nonzero) digits is 62208, while the sum is 41.

The spelling of 816131640029 in words is "eight hundred sixteen billion, one hundred thirty-one million, six hundred forty thousand, twenty-nine".