21312033440 has 48 divisors (see below), whose sum is σ = 51420966912. Its totient is φ = 8343431424.

The previous prime is 21312033439. The next prime is 21312033451. The reversal of 21312033440 is 4433021312.

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 7 ways as a sum of consecutive naturals, for example, 1409504 + ... + 1424543.

It is an arithmetic number, because the mean of its divisors is an integer number (1071270144).

Almost surely, 2^21312033440 is an apocalyptic number.

21312033440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21312033440 is an abundant number, since it is smaller than the sum of its proper divisors (30108933472).

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

21312033440 is a wasteful number, since it uses less digits than its factorization.

21312033440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2834109 (or 2834101 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 23.

Adding to 21312033440 its reverse (4433021312), we get a palindrome (25745054752).

The spelling of 21312033440 in words is "twenty-one billion, three hundred twelve million, thirty-three thousand, four hundred forty".