21311344000 has 64 divisors (see below), whose sum is σ = 52985368800. Its totient is φ = 8524531200.

The previous prime is 21311343983. The next prime is 21311344001. The reversal of 21311344000 is 44311312.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21311344001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 649980 + ... + 681979.

Almost surely, 2^21311344000 is an apocalyptic number.

21311344000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21311344000 is an abundant number, since it is smaller than the sum of its proper divisors (31674024800).

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

21311344000 is an equidigital number, since it uses as much as digits as its factorization.

21311344000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1331988 (or 1331966 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21311344000 its reverse (44311312), we get a palindrome (21355655312).

The spelling of 21311344000 in words is "twenty-one billion, three hundred eleven million, three hundred forty-four thousand".