21421123140 has 96 divisors (see below), whose sum is σ = 62654570496. Its totient is φ = 5458034560.

The previous prime is 21421123111. The next prime is 21421123187. The reversal of 21421123140 is 4132112412.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1348645 + ... + 1364435.

It is an arithmetic number, because the mean of its divisors is an integer number (652651776).

Almost surely, 2^21421123140 is an apocalyptic number.

21421123140 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 21421123140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31327285248).

21421123140 is an abundant number, since it is smaller than the sum of its proper divisors (41233447356).

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

21421123140 is a wasteful number, since it uses less digits than its factorization.

21421123140 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16809 (or 16807 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 21.

Adding to 21421123140 its reverse (4132112412), we get a palindrome (25553235552).

The spelling of 21421123140 in words is "twenty-one billion, four hundred twenty-one million, one hundred twenty-three thousand, one hundred forty".