81817476 has 48 divisors (see below), whose sum is σ = 210391104. Its totient is φ = 24587136.

The previous prime is 81817453. The next prime is 81817487. The reversal of 81817476 is 67471818.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 610 + ... + 12806.

It is an arithmetic number, because the mean of its divisors is an integer number (4383148).

Almost surely, 2^81817476 is an apocalyptic number.

81817476 is a gapful number since it is divisible by the number (86) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81817476, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105195552).

81817476 is an abundant number, since it is smaller than the sum of its proper divisors (128573628).

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

81817476 is a wasteful number, since it uses less digits than its factorization.

81817476 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12260 (or 12258 counting only the distinct ones).

The product of its digits is 75264, while the sum is 42.

The square root of 81817476 is about 9045.3013216808. The cubic root of 81817476 is about 434.1255627123.

The spelling of 81817476 in words is "eighty-one million, eight hundred seventeen thousand, four hundred seventy-six".