81275850 has 72 divisors (see below), whose sum is σ = 220497420. Its totient is φ = 21461760.

The previous prime is 81275849. The next prime is 81275879. The reversal of 81275850 is 5857218.

It can be written as a sum of positive squares in 6 ways, for example, as 29909961 + 51365889 = 5469^2 + 7167^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 48222 + ... + 49878.

Almost surely, 2^81275850 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81275850, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110248710).

81275850 is an abundant number, since it is smaller than the sum of its proper divisors (139221570).

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

81275850 is a wasteful number, since it uses less digits than its factorization.

81275850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1784 (or 1776 counting only the distinct ones).

The product of its (nonzero) digits is 22400, while the sum is 36.

The square root of 81275850 is about 9015.3119746352. The cubic root of 81275850 is about 433.1654806839.

The spelling of 81275850 in words is "eighty-one million, two hundred seventy-five thousand, eight hundred fifty".