1981609532918 has 16 divisors (see below), whose sum is σ = 3042021620880. Its totient is φ = 967609620096.

The previous prime is 1981609532909. The next prime is 1981609532923. The reversal of 1981609532918 is 8192359061891.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1276055 + ... + 2364642.

It is an arithmetic number, because the mean of its divisors is an integer number (190126351305).

Almost surely, 2^{1981609532918} is an apocalyptic number.

1981609532918 is a deficient number, since it is larger than the sum of its proper divisors (1060412087962).

1981609532918 is a wasteful number, since it uses less digits than its factorization.

1981609532918 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3647071.

The product of its (nonzero) digits is 8398080, while the sum is 62.

The spelling of 1981609532918 in words is "one trillion, nine hundred eighty-one billion, six hundred nine million, five hundred thirty-two thousand, nine hundred eighteen".