21113310440 has 32 divisors (see below), whose sum is σ = 47667107880. Its totient is φ = 8416495872.

The previous prime is 21113310433. The next prime is 21113310443. The reversal of 21113310440 is 4401331112.

It can be written as a sum of positive squares in 4 ways, for example, as 16901560036 + 4211750404 = 130006^2 + 64898^2 .

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

It is not an unprimeable number, because it can be changed into a prime (21113310443) 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, 889019 + ... + 912458.

Almost surely, 2^21113310440 is an apocalyptic number.

21113310440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21113310440 is an abundant number, since it is smaller than the sum of its proper divisors (26553797440).

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

21113310440 is a wasteful number, since it uses less digits than its factorization.

21113310440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1801781 (or 1801777 counting only the distinct ones).

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

Adding to 21113310440 its reverse (4401331112), we get a palindrome (25514641552).

The spelling of 21113310440 in words is "twenty-one billion, one hundred thirteen million, three hundred ten thousand, four hundred forty".