21113111440 has 20 divisors (see below), whose sum is σ = 49087984284. Its totient is φ = 8445244544.

The previous prime is 21113111423. The next prime is 21113111443. The reversal of 21113111440 is 4411131112.

It can be written as a sum of positive squares in 2 ways, for example, as 14685561856 + 6427549584 = 121184^2 + 80172^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (21113111443) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 131956867 + ... + 131957026.

Almost surely, 2^21113111440 is an apocalyptic number.

21113111440 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21113111440 is an abundant number, since it is smaller than the sum of its proper divisors (27974872844).

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

21113111440 is a wasteful number, since it uses less digits than its factorization.

21113111440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 263913906 (or 263913900 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 21113111440 its reverse (4411131112), we get a palindrome (25524242552).

The spelling of 21113111440 in words is "twenty-one billion, one hundred thirteen million, one hundred eleven thousand, four hundred forty".