81313648 has 60 divisors (see below), whose sum is σ = 177601480. Its totient is φ = 35849088.

The previous prime is 81313643. The next prime is 81313649. The reversal of 81313648 is 84631318.

It is a super-2 number, since 2×81313648² = 13223818702135808, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81313643) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 109663 + ... + 110401.

Almost surely, 2^81313648 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 81313648, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88800740).

81313648 is an abundant number, since it is smaller than the sum of its proper divisors (96287832).

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

81313648 is a wasteful number, since it uses less digits than its factorization.

81313648 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 806 (or 777 counting only the distinct ones).

The product of its digits is 13824, while the sum is 34.

The square root of 81313648 is about 9017.4080533155. The cubic root of 81313648 is about 433.2326193292.

The spelling of 81313648 in words is "eighty-one million, three hundred thirteen thousand, six hundred forty-eight".