21313144240 has 40 divisors (see below), whose sum is σ = 50231883168. Its totient is φ = 8408471040.

The previous prime is 21313144217. The next prime is 21313144249. The reversal of 21313144240 is 4244131312.

It is a tau number, because it is divible by the number of its divisors (40).

It is not an unprimeable number, because it can be changed into a prime (21313144249) 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, 1818916 + ... + 1830595.

Almost surely, 2^21313144240 is an apocalyptic number.

21313144240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21313144240 is an abundant number, since it is smaller than the sum of its proper divisors (28918738928).

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

21313144240 is a wasteful number, since it uses less digits than its factorization.

21313144240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3649597 (or 3649591 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 25.

Adding to 21313144240 its reverse (4244131312), we get a palindrome (25557275552).

The spelling of 21313144240 in words is "twenty-one billion, three hundred thirteen million, one hundred forty-four thousand, two hundred forty".