21123140140 has 48 divisors (see below), whose sum is σ = 45486080640. Its totient is φ = 8234910720.

The previous prime is 21123140119. The next prime is 21123140149. The reversal of 21123140140 is 4104132112.

It is not an unprimeable number, because it can be changed into a prime (21123140149) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 839584 + ... + 864376.

It is an arithmetic number, because the mean of its divisors is an integer number (947626680).

Almost surely, 2^21123140140 is an apocalyptic number.

21123140140 is a gapful number since it is divisible by the number (20) 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 21123140140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22743040320).

21123140140 is an abundant number, since it is smaller than the sum of its proper divisors (24362940500).

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

21123140140 is a wasteful number, since it uses less digits than its factorization.

21123140140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25882 (or 25880 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 21123140140 its reverse (4104132112), we get a palindrome (25227272252).

The spelling of 21123140140 in words is "twenty-one billion, one hundred twenty-three million, one hundred forty thousand, one hundred forty".