21420213120 has 192 divisors, whose sum is σ = 74064790800. Its totient is φ = 5704482816.

The previous prime is 21420213119. The next prime is 21420213137. The reversal of 21420213120 is 2131202412.

It is a happy number.

21420213120 is a `hidden beast` number, since 21 + 420 + 213 + 12 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21420213093 and 21420213102.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5349039 + ... + 5353041.

Almost surely, 2^21420213120 is an apocalyptic number.

21420213120 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 21420213120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37032395400).

21420213120 is an abundant number, since it is smaller than the sum of its proper divisors (52644577680).

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

21420213120 is a wasteful number, since it uses less digits than its factorization.

21420213120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4957 (or 4942 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

Adding to 21420213120 its reverse (2131202412), we get a palindrome (23551415532).

The spelling of 21420213120 in words is "twenty-one billion, four hundred twenty million, two hundred thirteen thousand, one hundred twenty".