21130320420 has 96 divisors (see below), whose sum is σ = 71715047040. Its totient is φ = 5122500480.

The previous prime is 21130320401. The next prime is 21130320433. The reversal of 21130320420 is 2402303112.

21130320420 is a `hidden beast` number, since 211 + 3 + 0 + 32 + 0 + 420 = 666.

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 = 21130320393 and 21130320402.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1772707 + ... + 1784586.

It is an arithmetic number, because the mean of its divisors is an integer number (747031740).

Almost surely, 2^21130320420 is an apocalyptic number.

21130320420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21130320420 is an abundant number, since it is smaller than the sum of its proper divisors (50584726620).

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

21130320420 is a wasteful number, since it uses less digits than its factorization.

21130320420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3557322 (or 3557314 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21130320420 its reverse (2402303112), we get a palindrome (23532623532).

The spelling of 21130320420 in words is "twenty-one billion, one hundred thirty million, three hundred twenty thousand, four hundred twenty".