81819276 has 96 divisors (see below), whose sum is σ = 241479168. Its totient is φ = 20943360.

The previous prime is 81819229. The next prime is 81819281. The reversal of 81819276 is 67291818.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 66846 + ... + 68058.

It is an arithmetic number, because the mean of its divisors is an integer number (2515408).

Almost surely, 2^81819276 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 81819276, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120739584).

81819276 is an abundant number, since it is smaller than the sum of its proper divisors (159659892).

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

81819276 is a wasteful number, since it uses less digits than its factorization.

81819276 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1311 (or 1309 counting only the distinct ones).

The product of its digits is 48384, while the sum is 42.

The square root of 81819276 is about 9045.4008203064. The cubic root of 81819276 is about 434.1287463038.

The spelling of 81819276 in words is "eighty-one million, eight hundred nineteen thousand, two hundred seventy-six".