21313444240 has 80 divisors (see below), whose sum is σ = 54084752640. Its totient is φ = 7746600960.

The previous prime is 21313444231. The next prime is 21313444277. The reversal of 21313444240 is 4244431312.

It is a tau number, because it is divible by the number of its divisors (80).

It is a junction number, because it is equal to n+sod(n) for n = 21313444199 and 21313444208.

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, 2361817 + ... + 2370823.

It is an arithmetic number, because the mean of its divisors is an integer number (676059408).

Almost surely, 2^21313444240 is an apocalyptic number.

21313444240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21313444240 is an abundant number, since it is smaller than the sum of its proper divisors (32771308400).

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

21313444240 is a wasteful number, since it uses less digits than its factorization.

21313444240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11720 (or 11714 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 28.

Adding to 21313444240 its reverse (4244431312), we get a palindrome (25557875552).

The spelling of 21313444240 in words is "twenty-one billion, three hundred thirteen million, four hundred forty-four thousand, two hundred forty".