21140431420 has 48 divisors (see below), whose sum is σ = 45502113888. Its totient is φ = 8245923840.

The previous prime is 21140431381. The next prime is 21140431427. The reversal of 21140431420 is 2413404112.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21140431391 and 21140431400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21140431427) 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, 510700 + ... + 550540.

It is an arithmetic number, because the mean of its divisors is an integer number (947960706).

Almost surely, 2^21140431420 is an apocalyptic number.

21140431420 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 21140431420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22751056944).

21140431420 is an abundant number, since it is smaller than the sum of its proper divisors (24361682468).

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

21140431420 is a wasteful number, since it uses less digits than its factorization.

21140431420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40510 (or 40508 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 22.

Adding to 21140431420 its reverse (2413404112), we get a palindrome (23553835532).

The spelling of 21140431420 in words is "twenty-one billion, one hundred forty million, four hundred thirty-one thousand, four hundred twenty".