81689148 has 60 divisors (see below), whose sum is σ = 226128672. Its totient is φ = 25626240.

The previous prime is 81689129. The next prime is 81689171. The reversal of 81689148 is 84198618.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1908 + ... + 12923.

Almost surely, 2^81689148 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 81689148, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113064336).

81689148 is an abundant number, since it is smaller than the sum of its proper divisors (144439524).

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

81689148 is a wasteful number, since it uses less digits than its factorization.

81689148 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14864 (or 14853 counting only the distinct ones).

The product of its digits is 110592, while the sum is 45.

The square root of 81689148 is about 9038.2049102684. The cubic root of 81689148 is about 433.8984734235.

The spelling of 81689148 in words is "eighty-one million, six hundred eighty-nine thousand, one hundred forty-eight".