81122979416 has 16 divisors (see below), whose sum is σ = 153611583840. Its totient is φ = 40159890400.

The previous prime is 81122979407. The next prime is 81122979419. The reversal of 81122979416 is 61497922118.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81122979419) 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 3 ways as a sum of consecutive naturals, for example, 50199056 + ... + 50200671.

It is an arithmetic number, because the mean of its divisors is an integer number (9600723990).

Almost surely, 2^81122979416 is an apocalyptic number.

It is an amenable number.

81122979416 is a deficient number, since it is larger than the sum of its proper divisors (72488604424).

81122979416 is a wasteful number, since it uses less digits than its factorization.

81122979416 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100399834 (or 100399830 counting only the distinct ones).

The product of its digits is 435456, while the sum is 50.

The spelling of 81122979416 in words is "eighty-one billion, one hundred twenty-two million, nine hundred seventy-nine thousand, four hundred sixteen".