81889600 has 168 divisors, whose sum is σ = 225763328. Its totient is φ = 29030400.

The previous prime is 81889597. The next prime is 81889603. The reversal of 81889600 is 698818.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (81889597) and next prime (81889603).

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81889603) 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, 644737 + ... + 644863.

Almost surely, 2^81889600 is an apocalyptic number.

81889600 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 81889600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112881664).

81889600 is an abundant number, since it is smaller than the sum of its proper divisors (143873728).

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

81889600 is a wasteful number, since it uses less digits than its factorization.

81889600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193 (or 178 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 40.

The square root of 81889600 is about 9049.2872647518. The cubic root of 81889600 is about 434.2530891597.

The spelling of 81889600 in words is "eighty-one million, eight hundred eighty-nine thousand, six hundred".