81849600 has 486 divisors, whose sum is σ = 352145430. Its totient is φ = 18063360.

The previous prime is 81849583. The next prime is 81849619. The reversal of 81849600 is 694818.

It is a happy number.

81849600 is a `hidden beast` number, since 8 + 1 + 8 + 49 + 600 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 5531904 + 76317696 = 2352^2 + 8736^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 53 ways as a sum of consecutive naturals, for example, 2822386 + ... + 2822414.

Almost surely, 2^81849600 is an apocalyptic number.

81849600 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81849600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (176072715).

81849600 is an abundant number, since it is smaller than the sum of its proper divisors (270295830).

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

81849600 is a wasteful number, since it uses less digits than its factorization.

81849600 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 75 (or 46 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 36.

The square root of 81849600 is about 9047.0768759860. The cubic root of 81849600 is about 434.1823721922.

The spelling of 81849600 in words is "eighty-one million, eight hundred forty-nine thousand, six hundred".