81247086 has 36 divisors (see below), whose sum is σ = 184104648. Its totient is φ = 25846392.

The previous prime is 81247073. The next prime is 81247087. The reversal of 81247086 is 68074218.

It is a self number, because there is not a number n which added to its sum of digits gives 81247086.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81247087) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 183181 + ... + 183623.

It is an arithmetic number, because the mean of its divisors is an integer number (5114018).

Almost surely, 2^81247086 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81247086, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92052324).

81247086 is an abundant number, since it is smaller than the sum of its proper divisors (102857562).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81247086 is a wasteful number, since it uses less digits than its factorization.

81247086 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 917 (or 471 counting only the distinct ones).

The product of its (nonzero) digits is 21504, while the sum is 36.

The square root of 81247086 is about 9013.7165475735. The cubic root of 81247086 is about 433.1143747198.

The spelling of 81247086 in words is "eighty-one million, two hundred forty-seven thousand, eighty-six".