21120310420 has 72 divisors (see below), whose sum is σ = 48784280832. Its totient is φ = 7674912960.

The previous prime is 21120310411. The next prime is 21120310457. The reversal of 21120310420 is 2401302112.

It is a junction number, because it is equal to n+sod(n) for n = 21120310394 and 21120310403.

It is a congruent number.

It is an unprimeable number.

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 23 ways as a sum of consecutive naturals, for example, 6985029 + ... + 6988051.

It is an arithmetic number, because the mean of its divisors is an integer number (677559456).

Almost surely, 2^21120310420 is an apocalyptic number.

21120310420 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 21120310420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24392140416).

21120310420 is an abundant number, since it is smaller than the sum of its proper divisors (27663970412).

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

21120310420 is a wasteful number, since it uses less digits than its factorization.

21120310420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5941 (or 5928 counting only the distinct ones).

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

Adding to 21120310420 its reverse (2401302112), we get a palindrome (23521612532).

The spelling of 21120310420 in words is "twenty-one billion, one hundred twenty million, three hundred ten thousand, four hundred twenty".