81955979418 has 8 divisors (see below), whose sum is σ = 163911958848. Its totient is φ = 27318659804.

The previous prime is 81955979411. The next prime is 81955979449. The reversal of 81955979418 is 81497955918.

It is a sphenic number, since it is the product of 3 distinct primes.

81955979418 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (81955979411) 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, 6829664946 + ... + 6829664957.

It is an arithmetic number, because the mean of its divisors is an integer number (20488994856).

Almost surely, 2^81955979418 is an apocalyptic number.

81955979418 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

81955979418 is a wasteful number, since it uses less digits than its factorization.

81955979418 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13659329908.

The product of its digits is 32659200, while the sum is 66.

The spelling of 81955979418 in words is "eighty-one billion, nine hundred fifty-five million, nine hundred seventy-nine thousand, four hundred eighteen".