81678750 has 80 divisors (see below), whose sum is σ = 213231744. Its totient is φ = 20812000.

The previous prime is 81678749. The next prime is 81678781. The reversal of 81678750 is 5787618.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 85777 + ... + 86723.

Almost surely, 2^81678750 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 81678750, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106615872).

81678750 is an abundant number, since it is smaller than the sum of its proper divisors (131552994).

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

81678750 is a wasteful number, since it uses less digits than its factorization.

81678750 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 995 (or 980 counting only the distinct ones).

The product of its (nonzero) digits is 94080, while the sum is 42.

The square root of 81678750 is about 9037.6296671196. The cubic root of 81678750 is about 433.8800627049.

It can be divided in two parts, 81678 and 750, that added together give a palindrome (82428).

The spelling of 81678750 in words is "eighty-one million, six hundred seventy-eight thousand, seven hundred fifty".