81295784 has 16 divisors (see below), whose sum is σ = 156148020. Its totient is φ = 39656320.

The previous prime is 81295783. The next prime is 81295789. The reversal of 81295784 is 48759218.

It can be written as a sum of positive squares in 2 ways, for example, as 63840100 + 17455684 = 7990^2 + 4178^2 .

It is not an unprimeable number, because it can be changed into a prime (81295783) 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 3 ways as a sum of consecutive naturals, for example, 123599 + ... + 124254.

Almost surely, 2^81295784 is an apocalyptic number.

It is an amenable number.

81295784 is a deficient number, since it is larger than the sum of its proper divisors (74852236).

81295784 is a wasteful number, since it uses less digits than its factorization.

81295784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247900 (or 247896 counting only the distinct ones).

The product of its digits is 161280, while the sum is 44.

The square root of 81295784 is about 9016.4174703704. The cubic root of 81295784 is about 433.2008910174.

The spelling of 81295784 in words is "eighty-one million, two hundred ninety-five thousand, seven hundred eighty-four".