81616731822 has 24 divisors (see below), whose sum is σ = 177131494800. Its totient is φ = 27160155360.

The previous prime is 81616731821. The next prime is 81616731839. The reversal of 81616731822 is 22813761618.

81616731822 is a `hidden beast` number, since 8 + 1 + 616 + 7 + 3 + 1 + 8 + 22 = 666.

It is a super-2 number, since 2×81616731822² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81616731821) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3774079 + ... + 3795642.

It is an arithmetic number, because the mean of its divisors is an integer number (7380478950).

Almost surely, 2^81616731822 is an apocalyptic number.

81616731822 is an abundant number, since it is smaller than the sum of its proper divisors (95514762978).

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

81616731822 is a wasteful number, since it uses less digits than its factorization.

81616731822 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7570328 (or 7570325 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The spelling of 81616731822 in words is "eighty-one billion, six hundred sixteen million, seven hundred thirty-one thousand, eight hundred twenty-two".