18129136820 has 72 divisors (see below), whose sum is σ = 40345327176. Its totient is φ = 6841055232.

The previous prime is 18129136757. The next prime is 18129136849. The reversal of 18129136820 is 2863192181.

It can be written as a sum of positive squares in 4 ways, for example, as 7454940964 + 10674195856 = 86342^2 + 103316^2 .

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 760604 + ... + 784076.

Almost surely, 2^18129136820 is an apocalyptic number.

18129136820 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18129136820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20172663588).

18129136820 is an abundant number, since it is smaller than the sum of its proper divisors (22216190356).

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

18129136820 is a wasteful number, since it uses less digits than its factorization.

18129136820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23601 (or 23576 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 41.

The spelling of 18129136820 in words is "eighteen billion, one hundred twenty-nine million, one hundred thirty-six thousand, eight hundred twenty".