81678336 has 156 divisors (see below), whose sum is σ = 241405152. Its totient is φ = 24510464.

The previous prime is 81678323. The next prime is 81678347. The reversal of 81678336 is 63387618.

Its product of digits (145152) is a multiple of the sum of its prime factors (84).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3551221 + ... + 3551243.

Almost surely, 2^81678336 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 81678336, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (120702576).

81678336 is an abundant number, since it is smaller than the sum of its proper divisors (159726816).

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

81678336 is a wasteful number, since it uses less digits than its factorization.

81678336 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84 (or 45 counting only the distinct ones).

The product of its digits is 145152, while the sum is 42.

The square root of 81678336 is about 9037.6067628549. The cubic root of 81678336 is about 433.8793296433.

The spelling of 81678336 in words is "eighty-one million, six hundred seventy-eight thousand, three hundred thirty-six".