81122784 has 48 divisors (see below), whose sum is σ = 219824640. Its totient is φ = 26167680.

The previous prime is 81122779. The next prime is 81122791. The reversal of 81122784 is 48722118.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (48).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10654 + ... + 16605.

It is an arithmetic number, because the mean of its divisors is an integer number (4579680).

Almost surely, 2^81122784 is an apocalyptic number.

It is an amenable number.

81122784 is an abundant number, since it is smaller than the sum of its proper divisors (138701856).

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

81122784 is a wasteful number, since it uses less digits than its factorization.

81122784 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27303 (or 27295 counting only the distinct ones).

The product of its digits is 7168, while the sum is 33.

The square root of 81122784 is about 9006.8187502581. The cubic root of 81122784 is about 432.8933843863.

The spelling of 81122784 in words is "eighty-one million, one hundred twenty-two thousand, seven hundred eighty-four".