21113013440 has 28 divisors (see below), whose sum is σ = 50275364016. Its totient is φ = 8445205248.

The previous prime is 21113013413. The next prime is 21113013547. The reversal of 21113013440 is 4431031112.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32988764 + ... + 32989403.

Almost surely, 2^21113013440 is an apocalyptic number.

21113013440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21113013440 is an abundant number, since it is smaller than the sum of its proper divisors (29162350576).

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

21113013440 is an equidigital number, since it uses as much as digits as its factorization.

21113013440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65978184 (or 65978174 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 21113013440 its reverse (4431031112), we get a palindrome (25544044552).

The spelling of 21113013440 in words is "twenty-one billion, one hundred thirteen million, thirteen thousand, four hundred forty".