81845454819 has 4 divisors (see below), whose sum is σ = 109127273096. Its totient is φ = 54563636544.

The previous prime is 81845454809. The next prime is 81845454863. The reversal of 81845454819 is 91845454818.

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

It is not a de Polignac number, because 81845454819 - 2⁹ = 81845454307 is a prime.

It is a super-2 number, since 2×81845454819² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81845454809) 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, 13640909134 + ... + 13640909139.

It is an arithmetic number, because the mean of its divisors is an integer number (27281818274).

Almost surely, 2^81845454819 is an apocalyptic number.

81845454819 is a deficient number, since it is larger than the sum of its proper divisors (27281818277).

81845454819 is a wasteful number, since it uses less digits than its factorization.

81845454819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27281818276.

The product of its digits is 7372800, while the sum is 57.

Subtracting 81845454819 from its reverse (91845454818), we obtain a palindrome (9999999999).

The spelling of 81845454819 in words is "eighty-one billion, eight hundred forty-five million, four hundred fifty-four thousand, eight hundred nineteen".