81838944 has 192 divisors, whose sum is σ = 266112000. Its totient is φ = 24261120.

The previous prime is 81838937. The next prime is 81838951. The reversal of 81838944 is 44983818.

It is an interprime number because it is at equal distance from previous prime (81838937) and next prime (81838951).

It is a super-2 number, since 2×81838944² = 13395225510070272, which contains 22 as substring.

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

It is a self number, because there is not a number n which added to its sum of digits gives 81838944.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 750762 + ... + 750870.

It is an arithmetic number, because the mean of its divisors is an integer number (1386000).

Almost surely, 2^81838944 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 81838944, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (133056000).

81838944 is an abundant number, since it is smaller than the sum of its proper divisors (184273056).

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

81838944 is a wasteful number, since it uses less digits than its factorization.

81838944 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218 (or 204 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The square root of 81838944 is about 9046.4879373158. The cubic root of 81838944 is about 434.1635293058.

The spelling of 81838944 in words is "eighty-one million, eight hundred thirty-eight thousand, nine hundred forty-four".