21100213420 has 48 divisors (see below), whose sum is σ = 52057037088. Its totient is φ = 7082588160.

The previous prime is 21100213367. The next prime is 21100213427. The reversal of 21100213420 is 2431200112.

It is a junction number, because it is equal to n+sod(n) for n = 21100213394 and 21100213403.

It is not an unprimeable number, because it can be changed into a prime (21100213427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3685989 + ... + 3691708.

It is an arithmetic number, because the mean of its divisors is an integer number (1084521606).

Almost surely, 2^21100213420 is an apocalyptic number.

21100213420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100213420 is an abundant number, since it is smaller than the sum of its proper divisors (30956823668).

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

21100213420 is a wasteful number, since it uses less digits than its factorization.

21100213420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7377730 (or 7377728 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21100213420 its reverse (2431200112), we get a palindrome (23531413532).

It can be divided in two parts, 211002 and 13420, that added together give a palindrome (224422).

The spelling of 21100213420 in words is "twenty-one billion, one hundred million, two hundred thirteen thousand, four hundred twenty".