81361248 has 48 divisors (see below), whose sum is σ = 216167616. Its totient is φ = 26791040.

The previous prime is 81361213. The next prime is 81361253. The reversal of 81361248 is 84216318.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-2 number, since 2×81361248² = 13239305352235008, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

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 7 ways as a sum of consecutive naturals, for example, 2863 + ... + 13073.

It is an arithmetic number, because the mean of its divisors is an integer number (4503492).

Almost surely, 2^81361248 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 81361248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (108083808).

81361248 is an abundant number, since it is smaller than the sum of its proper divisors (134806368).

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

81361248 is a wasteful number, since it uses less digits than its factorization.

81361248 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10307 (or 10299 counting only the distinct ones).

The product of its digits is 9216, while the sum is 33.

The square root of 81361248 is about 9020.0470065294. The cubic root of 81361248 is about 433.3171391713.

The spelling of 81361248 in words is "eighty-one million, three hundred sixty-one thousand, two hundred forty-eight".