21121044140 has 48 divisors (see below), whose sum is σ = 50973753600. Its totient is φ = 7201036992.

The previous prime is 21121044089. The next prime is 21121044211. The reversal of 21121044140 is 4144012112.

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 (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 396350 + ... + 446469.

It is an arithmetic number, because the mean of its divisors is an integer number (1061953200).

Almost surely, 2^21121044140 is an apocalyptic number.

21121044140 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21121044140 is an abundant number, since it is smaller than the sum of its proper divisors (29852709460).

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

21121044140 is a wasteful number, since it uses less digits than its factorization.

21121044140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 843014 (or 843012 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 21121044140 its reverse (4144012112), we get a palindrome (25265056252).

The spelling of 21121044140 in words is "twenty-one billion, one hundred twenty-one million, forty-four thousand, one hundred forty".