81008454979 has 4 divisors (see below), whose sum is σ = 81461016360. Its totient is φ = 80555893600.

The previous prime is 81008454959. The next prime is 81008454991. The reversal of 81008454979 is 97945480018.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81008454979 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81008454959) 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, 226280422 + ... + 226280779.

It is an arithmetic number, because the mean of its divisors is an integer number (20365254090).

Almost surely, 2^81008454979 is an apocalyptic number.

81008454979 is a deficient number, since it is larger than the sum of its proper divisors (452561381).

81008454979 is a wasteful number, since it uses less digits than its factorization.

81008454979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 452561380.

The product of its (nonzero) digits is 2903040, while the sum is 55.

The spelling of 81008454979 in words is "eighty-one billion, eight million, four hundred fifty-four thousand, nine hundred seventy-nine".