81539122 has 16 divisors (see below), whose sum is σ = 142420032. Its totient is φ = 34285680.

The previous prime is 81539099. The next prime is 81539141. The reversal of 81539122 is 22193518.

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 7 ways as a sum of consecutive naturals, for example, 54204 + ... + 55687.

It is an arithmetic number, because the mean of its divisors is an integer number (8901252).

Almost surely, 2^81539122 is an apocalyptic number.

81539122 is a deficient number, since it is larger than the sum of its proper divisors (60880910).

81539122 is a wasteful number, since it uses less digits than its factorization.

81539122 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109953.

The product of its digits is 4320, while the sum is 31.

The square root of 81539122 is about 9029.9015498509. The cubic root of 81539122 is about 433.6326855952.

The spelling of 81539122 in words is "eighty-one million, five hundred thirty-nine thousand, one hundred twenty-two".