21312033420 has 48 divisors (see below), whose sum is σ = 59680389888. Its totient is φ = 5682571200.

The previous prime is 21312033409. The next prime is 21312033433. The reversal of 21312033420 is 2433021312.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 793857 + ... + 820263.

It is an arithmetic number, because the mean of its divisors is an integer number (1243341456).

Almost surely, 2^21312033420 is an apocalyptic number.

21312033420 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21312033420 is an abundant number, since it is smaller than the sum of its proper divisors (38368356468).

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

21312033420 is a wasteful number, since it uses less digits than its factorization.

21312033420 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 39870 (or 39868 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 21.

Adding to 21312033420 its reverse (2433021312), we get a palindrome (23745054732).

The spelling of 21312033420 in words is "twenty-one billion, three hundred twelve million, thirty-three thousand, four hundred twenty".