21103443420 has 48 divisors (see below), whose sum is σ = 59131232160. Its totient is φ = 5623623936.

The previous prime is 21103443407. The next prime is 21103443443. The reversal of 21103443420 is 2434430112.

It is a super-2 number, since 2×21103443420² (a number of 21 digits) contains 22 as substring.

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 15 ways as a sum of consecutive naturals, for example, 37327 + ... + 208806.

It is an arithmetic number, because the mean of its divisors is an integer number (1231900670).

Almost surely, 2^21103443420 is an apocalyptic number.

21103443420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21103443420 is an abundant number, since it is smaller than the sum of its proper divisors (38027788740).

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

21103443420 is a wasteful number, since it uses less digits than its factorization.

21103443420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 247574 (or 247572 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 24.

Adding to 21103443420 its reverse (2434430112), we get a palindrome (23537873532).

The spelling of 21103443420 in words is "twenty-one billion, one hundred three million, four hundred forty-three thousand, four hundred twenty".