21015110180 has 48 divisors (see below), whose sum is σ = 45577943040. Its totient is φ = 8130844800.

The previous prime is 21015110153. The next prime is 21015110213. The reversal of 21015110180 is 8101151012.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1444181 + ... + 1458659.

It is an arithmetic number, because the mean of its divisors is an integer number (949540480).

Almost surely, 2^21015110180 is an apocalyptic number.

21015110180 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21015110180 is an abundant number, since it is smaller than the sum of its proper divisors (24562832860).

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

21015110180 is a wasteful number, since it uses less digits than its factorization.

21015110180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16860 (or 16858 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 20.

Adding to 21015110180 its reverse (8101151012), we get a palindrome (29116261192).

The spelling of 21015110180 in words is "twenty-one billion, fifteen million, one hundred ten thousand, one hundred eighty".