81706079 has 24 divisors (see below), whose sum is σ = 105910560. Its totient is φ = 62403264.

The previous prime is 81706067. The next prime is 81706109. The reversal of 81706079 is 97060718.

It is a happy number.

It is not a de Polignac number, because 81706079 - 2⁸ = 81705823 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81706039) 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, 16262 + ... + 20684.

It is an arithmetic number, because the mean of its divisors is an integer number (4412940).

Almost surely, 2^81706079 is an apocalyptic number.

81706079 is a deficient number, since it is larger than the sum of its proper divisors (24204481).

81706079 is a wasteful number, since it uses less digits than its factorization.

81706079 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4479 (or 4472 counting only the distinct ones).

The product of its (nonzero) digits is 21168, while the sum is 38.

The square root of 81706079 is about 9039.1414968458. The cubic root of 81706079 is about 433.9284481417.

The spelling of 81706079 in words is "eighty-one million, seven hundred six thousand, seventy-nine".