81718524 has 96 divisors (see below), whose sum is σ = 229340160. Its totient is φ = 25065216.

The previous prime is 81718519. The next prime is 81718529. The reversal of 81718524 is 42581718.

It is an interprime number because it is at equal distance from previous prime (81718519) and next prime (81718529).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81718529) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 85819 + ... + 86765.

It is an arithmetic number, because the mean of its divisors is an integer number (2388960).

Almost surely, 2^81718524 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81718524, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114670080).

81718524 is an abundant number, since it is smaller than the sum of its proper divisors (147621636).

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

81718524 is a wasteful number, since it uses less digits than its factorization.

81718524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1024 (or 1016 counting only the distinct ones).

The product of its digits is 17920, while the sum is 36.

The square root of 81718524 is about 9039.8298656557. The cubic root of 81718524 is about 433.9504781851.

The spelling of 81718524 in words is "eighty-one million, seven hundred eighteen thousand, five hundred twenty-four".