81137079 has 16 divisors (see below), whose sum is σ = 120342240. Its totient is φ = 54028800.

The previous prime is 81137071. The next prime is 81137113. The reversal of 81137079 is 97073118.

It is not a de Polignac number, because 81137079 - 2³ = 81137071 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81137071) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42289 + ... + 44165.

It is an arithmetic number, because the mean of its divisors is an integer number (7521390).

Almost surely, 2^81137079 is an apocalyptic number.

81137079 is a deficient number, since it is larger than the sum of its proper divisors (39205161).

81137079 is a wasteful number, since it uses less digits than its factorization.

81137079 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3487 (or 3481 counting only the distinct ones).

The product of its (nonzero) digits is 10584, while the sum is 36.

The square root of 81137079 is about 9007.6122807323. The cubic root of 81137079 is about 432.9188102374.

The spelling of 81137079 in words is "eighty-one million, one hundred thirty-seven thousand, seventy-nine".