81997848 has 96 divisors (see below), whose sum is σ = 232081200. Its totient is φ = 26121984.

The previous prime is 81997841. The next prime is 81997849. The reversal of 81997848 is 84879918.

It is a super-2 number, since 2×81997848² = 13447294153262208, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81997794 and 81997803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81997841) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 361111 + ... + 361337.

Almost surely, 2^81997848 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 81997848, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116040600).

81997848 is an abundant number, since it is smaller than the sum of its proper divisors (150083352).

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

81997848 is a wasteful number, since it uses less digits than its factorization.

81997848 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 441 (or 434 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 54.

The square root of 81997848 is about 9055.2663130357. The cubic root of 81997848 is about 434.4443480053. Note that the first 3 decimals are identical.

The spelling of 81997848 in words is "eighty-one million, nine hundred ninety-seven thousand, eight hundred forty-eight".