81749248 has 108 divisors (see below), whose sum is σ = 200393760. Its totient is φ = 33191424.

The previous prime is 81749197. The next prime is 81749249. The reversal of 81749248 is 84294718.

Its product of digits (129024) is a multiple of the sum of its prime divisors (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81749249) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4302583 + ... + 4302601.

Almost surely, 2^81749248 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 81749248, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (100196880).

81749248 is an abundant number, since it is smaller than the sum of its proper divisors (118644512).

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

81749248 is an frugal number, since it uses more digits than its factorization.

81749248 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 70 (or 28 counting only the distinct ones).

The product of its digits is 129024, while the sum is 43.

The square root of 81749248 is about 9041.5290742219. The cubic root of 81749248 is about 434.0048559984.

The spelling of 81749248 in words is "eighty-one million, seven hundred forty-nine thousand, two hundred forty-eight".