18312155728 has 20 divisors (see below), whose sum is σ = 35482991220. Its totient is φ = 9155254784.

The previous prime is 18312155723. The next prime is 18312155837. The reversal of 18312155728 is 82755121381.

It can be written as a sum of positive squares in 2 ways, for example, as 5752919104 + 12559236624 = 75848^2 + 112068^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18312155723) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 157926 + ... + 248122.

It is an arithmetic number, because the mean of its divisors is an integer number (1774149561).

Almost surely, 2^18312155728 is an apocalyptic number.

It is an amenable number.

18312155728 is a deficient number, since it is larger than the sum of its proper divisors (17170835492).

18312155728 is a wasteful number, since it uses less digits than its factorization.

18312155728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102894 (or 102888 counting only the distinct ones).

The product of its digits is 134400, while the sum is 43.

The spelling of 18312155728 in words is "eighteen billion, three hundred twelve million, one hundred fifty-five thousand, seven hundred twenty-eight".