81313248 has 96 divisors (see below), whose sum is σ = 223534080. Its totient is φ = 25850880.

The previous prime is 81313241. The next prime is 81313273. The reversal of 81313248 is 84231318.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×81313248² = 13223688600619008, 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 not an unprimeable number, because it can be changed into a prime (81313241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 264711 + ... + 265017.

It is an arithmetic number, because the mean of its divisors is an integer number (2328480).

Almost surely, 2^81313248 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 81313248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111767040).

81313248 is an abundant number, since it is smaller than the sum of its proper divisors (142220832).

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

81313248 is a wasteful number, since it uses less digits than its factorization.

81313248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 440 (or 432 counting only the distinct ones).

The product of its digits is 4608, while the sum is 30.

The square root of 81313248 is about 9017.3858739659. The cubic root of 81313248 is about 433.2319089387.

The spelling of 81313248 in words is "eighty-one million, three hundred thirteen thousand, two hundred forty-eight".