81887400 has 288 divisors, whose sum is σ = 322271040. Its totient is φ = 18247680.

The previous prime is 81887389. The next prime is 81887431. The reversal of 81887400 is 478818.

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

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 844152 + ... + 844248.

Almost surely, 2^81887400 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 81887400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (161135520).

81887400 is an abundant number, since it is smaller than the sum of its proper divisors (240383640).

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

81887400 is a wasteful number, since it uses less digits than its factorization.

81887400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 193 (or 181 counting only the distinct ones).

The product of its (nonzero) digits is 14336, while the sum is 36.

The square root of 81887400 is about 9049.1657074009. The cubic root of 81887400 is about 434.2492003251.

The spelling of 81887400 in words is "eighty-one million, eight hundred eighty-seven thousand, four hundred".