81707814 has 72 divisors (see below), whose sum is σ = 191089080. Its totient is φ = 25224192.

The previous prime is 81707789. The next prime is 81707833. The reversal of 81707814 is 41870718.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 587757 + ... + 587895.

It is an arithmetic number, because the mean of its divisors is an integer number (2654015).

Almost surely, 2^81707814 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81707814, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (95544540).

81707814 is an abundant number, since it is smaller than the sum of its proper divisors (109381266).

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

81707814 is a wasteful number, since it uses less digits than its factorization.

81707814 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294 (or 274 counting only the distinct ones).

The product of its (nonzero) digits is 12544, while the sum is 36.

The square root of 81707814 is about 9039.2374678399. The cubic root of 81707814 is about 433.9315195596.

The spelling of 81707814 in words is "eighty-one million, seven hundred seven thousand, eight hundred fourteen".