81439488 has 108 divisors (see below), whose sum is σ = 252965440. Its totient is φ = 25049088.

The previous prime is 81439483. The next prime is 81439493. The reversal of 81439488 is 88493418.

It is an interprime number because it is at equal distance from previous prime (81439483) and next prime (81439493).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (81439483) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 28593 + ... + 31311.

Almost surely, 2^81439488 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 81439488, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (126482720).

81439488 is an abundant number, since it is smaller than the sum of its proper divisors (171525952).

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

81439488 is a wasteful number, since it uses less digits than its factorization.

81439488 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2754 (or 2737 counting only the distinct ones).

The product of its digits is 221184, while the sum is 45.

The square root of 81439488 is about 9024.3829705969. The cubic root of 81439488 is about 433.4559926272.

It can be divided in two parts, 81 and 439488, that added together give a square (439569 = 663²).

The spelling of 81439488 in words is "eighty-one million, four hundred thirty-nine thousand, four hundred eighty-eight".