81826371819 has 24 divisors (see below), whose sum is σ = 120687417552. Its totient is φ = 53410855680.

The previous prime is 81826371727. The next prime is 81826371821. The reversal of 81826371819 is 91817362818.

It is not a de Polignac number, because 81826371819 - 2¹⁷ = 81826240747 is a prime.

It is a super-2 number, since 2×81826371819² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81826371859) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 364537 + ... + 544554.

It is an arithmetic number, because the mean of its divisors is an integer number (5028642398).

Almost surely, 2^81826371819 is an apocalyptic number.

81826371819 is a deficient number, since it is larger than the sum of its proper divisors (38861045733).

81826371819 is a wasteful number, since it uses less digits than its factorization.

81826371819 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 909307 (or 909304 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 54.

Subtracting 81826371819 from its reverse (91817362818), we obtain a palindrome (9990990999).

The spelling of 81826371819 in words is "eighty-one billion, eight hundred twenty-six million, three hundred seventy-one thousand, eight hundred nineteen".