81098784 has 72 divisors (see below), whose sum is σ = 248376492. Its totient is φ = 24952320.

The previous prime is 81098749. The next prime is 81098803. The reversal of 81098784 is 48789018.

It can be written as a sum of positive squares in 2 ways, for example, as 74442384 + 6656400 = 8628^2 + 2580^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is an unprimeable number.

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, 7087 + ... + 14574.

Almost surely, 2^81098784 is an apocalyptic number.

It is an amenable number.

81098784 is an abundant number, since it is smaller than the sum of its proper divisors (167277708).

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

81098784 is a wasteful number, since it uses less digits than its factorization.

81098784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21690 (or 21679 counting only the distinct ones).

The product of its (nonzero) digits is 129024, while the sum is 45.

The square root of 81098784 is about 9005.4863277893. The cubic root of 81098784 is about 432.8506899855.

The spelling of 81098784 in words is "eighty-one million, ninety-eight thousand, seven hundred eighty-four".