81239413336 has 16 divisors (see below), whose sum is σ = 152578206000. Its totient is φ = 40551891744.

The previous prime is 81239413243. The next prime is 81239413337. The reversal of 81239413336 is 63331493218.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 81239413292 and 81239413301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81239413337) 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, 8471775 + ... + 8481358.

It is an arithmetic number, because the mean of its divisors is an integer number (9536137875).

Almost surely, 2^81239413336 is an apocalyptic number.

It is an amenable number.

81239413336 is a deficient number, since it is larger than the sum of its proper divisors (71338792664).

81239413336 is a wasteful number, since it uses less digits than its factorization.

81239413336 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16953738 (or 16953734 counting only the distinct ones).

The product of its digits is 279936, while the sum is 43.

The spelling of 81239413336 in words is "eighty-one billion, two hundred thirty-nine million, four hundred thirteen thousand, three hundred thirty-six".