81641248 has 48 divisors (see below), whose sum is σ = 174053880. Its totient is φ = 37472256.

The previous prime is 81641243. The next prime is 81641251. The reversal of 81641248 is 84214618.

It can be written as a sum of positive squares in 4 ways, for example, as 81216144 + 425104 = 9012^2 + 652^2 .

It is not an unprimeable number, because it can be changed into a prime (81641243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 94836 + ... + 95692.

Almost surely, 2^81641248 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 81641248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (87026940).

81641248 is an abundant number, since it is smaller than the sum of its proper divisors (92412632).

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

81641248 is a wasteful number, since it uses less digits than its factorization.

81641248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1109 (or 1101 counting only the distinct ones).

The product of its digits is 12288, while the sum is 34.

The square root of 81641248 is about 9035.5546592337. The cubic root of 81641248 is about 433.8136486089.

The spelling of 81641248 in words is "eighty-one million, six hundred forty-one thousand, two hundred forty-eight".