81749376 has 96 divisors (see below), whose sum is σ = 243453600. Its totient is φ = 26299392.

The previous prime is 81749357. The next prime is 81749377. The reversal of 81749376 is 67394718.

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81749377) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 32185 + ... + 34631.

It is an arithmetic number, because the mean of its divisors is an integer number (2535975).

Almost surely, 2^81749376 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 81749376, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121726800).

81749376 is an abundant number, since it is smaller than the sum of its proper divisors (161704224).

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

81749376 is a wasteful number, since it uses less digits than its factorization.

81749376 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2496 (or 2481 counting only the distinct ones).

The product of its digits is 254016, while the sum is 45.

The square root of 81749376 is about 9041.5361526679. The cubic root of 81749376 is about 434.0050825146.

The spelling of 81749376 in words is "eighty-one million, seven hundred forty-nine thousand, three hundred seventy-six".