81836739 has 6 divisors (see below), whose sum is σ = 118208636. Its totient is φ = 54557820.

The previous prime is 81836731. The next prime is 81836773. The reversal of 81836739 is 93763818.

It is a happy number.

It is not a de Polignac number, because 81836739 - 2³ = 81836731 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81836694 and 81836703.

It is not an unprimeable number, because it can be changed into a prime (81836731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4546477 + ... + 4546494.

Almost surely, 2^81836739 is an apocalyptic number.

81836739 is a deficient number, since it is larger than the sum of its proper divisors (36371897).

81836739 is a wasteful number, since it uses less digits than its factorization.

81836739 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9092977 (or 9092974 counting only the distinct ones).

The product of its digits is 217728, while the sum is 45.

The square root of 81836739 is about 9046.3660659958. The cubic root of 81836739 is about 434.1596300245.

The spelling of 81836739 in words is "eighty-one million, eight hundred thirty-six thousand, seven hundred thirty-nine".