21120181940 has 96 divisors (see below), whose sum is σ = 54371955456. Its totient is φ = 6781040640.

The previous prime is 21120181913. The next prime is 21120181969. The reversal of 21120181940 is 4918102112.

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 31 ways as a sum of consecutive naturals, for example, 94757 + ... + 226316.

It is an arithmetic number, because the mean of its divisors is an integer number (566374536).

Almost surely, 2^21120181940 is an apocalyptic number.

21120181940 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21120181940 is an abundant number, since it is smaller than the sum of its proper divisors (33251773516).

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

21120181940 is a wasteful number, since it uses less digits than its factorization.

21120181940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321129 (or 321127 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 29.

The spelling of 21120181940 in words is "twenty-one billion, one hundred twenty million, one hundred eighty-one thousand, nine hundred forty".