21336312420 has 144 divisors (see below), whose sum is σ = 65421877248. Its totient is φ = 5628268800.

The previous prime is 21336312401. The next prime is 21336312461. The reversal of 21336312420 is 2421363312.

21336312420 is a `hidden beast` number, since 2 + 1 + 3 + 3 + 631 + 2 + 4 + 20 = 666.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9074245 + ... + 9076595.

It is an arithmetic number, because the mean of its divisors is an integer number (454318592).

Almost surely, 2^21336312420 is an apocalyptic number.

21336312420 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 21336312420, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32710938624).

21336312420 is an abundant number, since it is smaller than the sum of its proper divisors (44085564828).

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

21336312420 is a wasteful number, since it uses less digits than its factorization.

21336312420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2890 (or 2885 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 27.

Adding to 21336312420 its reverse (2421363312), we get a palindrome (23757675732).

The spelling of 21336312420 in words is "twenty-one billion, three hundred thirty-six million, three hundred twelve thousand, four hundred twenty".