81806088 has 96 divisors (see below), whose sum is σ = 256253760. Its totient is φ = 21571200.

The previous prime is 81806047. The next prime is 81806089. The reversal of 81806088 is 88060818.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is not an unprimeable number, because it can be changed into a prime (81806089) 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, 12613 + ... + 17963.

It is an arithmetic number, because the mean of its divisors is an integer number (2669310).

Almost surely, 2^81806088 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 81806088, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128126880).

81806088 is an abundant number, since it is smaller than the sum of its proper divisors (174447672).

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

81806088 is a wasteful number, since it uses less digits than its factorization.

81806088 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5387 (or 5376 counting only the distinct ones).

The product of its (nonzero) digits is 24576, while the sum is 39.

The square root of 81806088 is about 9044.6718016742. The cubic root of 81806088 is about 434.1054201073.

The spelling of 81806088 in words is "eighty-one million, eight hundred six thousand, eighty-eight".