81424874891 has 8 divisors (see below), whose sum is σ = 86623177104. Its totient is φ = 76271973120.

The previous prime is 81424874879. The next prime is 81424874893. The reversal of 81424874891 is 19847842418.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 81424874891 - 2¹⁰ = 81424873867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81424874893) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11346410 + ... + 11353583.

It is an arithmetic number, because the mean of its divisors is an integer number (10827897138).

Almost surely, 2^81424874891 is an apocalyptic number.

81424874891 is a deficient number, since it is larger than the sum of its proper divisors (5198302213).

81424874891 is a wasteful number, since it uses less digits than its factorization.

81424874891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22700221.

The product of its digits is 4128768, while the sum is 56.

The spelling of 81424874891 in words is "eighty-one billion, four hundred twenty-four million, eight hundred seventy-four thousand, eight hundred ninety-one".