21321043431420 has 96 divisors (see below), whose sum is σ = 60266295226368. Its totient is φ = 5631830294272.

The previous prime is 21321043431293. The next prime is 21321043431433. The reversal of 21321043431420 is 2413434012312.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1290012 + ... + 6656291.

It is an arithmetic number, because the mean of its divisors is an integer number (627773908608).

Almost surely, 2^{21321043431420} is an apocalyptic number.

21321043431420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21321043431420 is an abundant number, since it is smaller than the sum of its proper divisors (38945251794948).

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

21321043431420 is a wasteful number, since it uses less digits than its factorization.

21321043431420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7946739 (or 7946737 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 30.

Adding to 21321043431420 its reverse (2413434012312), we get a palindrome (23734477443732).

The spelling of 21321043431420 in words is "twenty-one trillion, three hundred twenty-one billion, forty-three million, four hundred thirty-one thousand, four hundred twenty".