21831272180 has 24 divisors (see below), whose sum is σ = 46028334240. Its totient is φ = 8697716000.

The previous prime is 21831272159. The next prime is 21831272233. The reversal of 21831272180 is 8127213812.

It is a self number, because there is not a number n which added to its sum of digits gives 21831272180.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2169410 + ... + 2179449.

It is an arithmetic number, because the mean of its divisors is an integer number (1917847260).

Almost surely, 2^21831272180 is an apocalyptic number.

21831272180 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21831272180 is an abundant number, since it is smaller than the sum of its proper divisors (24197062060).

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

21831272180 is a wasteful number, since it uses less digits than its factorization.

21831272180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4349119 (or 4349117 counting only the distinct ones).

The product of its (nonzero) digits is 10752, while the sum is 35.

Adding to 21831272180 its reverse (8127213812), we get a palindrome (29958485992).

The spelling of 21831272180 in words is "twenty-one billion, eight hundred thirty-one million, two hundred seventy-two thousand, one hundred eighty".