21113312240 has 40 divisors (see below), whose sum is σ = 51672057360. Its totient is φ = 8000833536.

The previous prime is 21113312179. The next prime is 21113312281. The reversal of 21113312240 is 4221331112.

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

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6943649 + ... + 6946688.

It is an arithmetic number, because the mean of its divisors is an integer number (1291801434).

Almost surely, 2^21113312240 is an apocalyptic number.

21113312240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21113312240 is an abundant number, since it is smaller than the sum of its proper divisors (30558745120).

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

21113312240 is a wasteful number, since it uses less digits than its factorization.

21113312240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13890369 (or 13890363 counting only the distinct ones).

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

Adding to 21113312240 its reverse (4221331112), we get a palindrome (25334643352).

The spelling of 21113312240 in words is "twenty-one billion, one hundred thirteen million, three hundred twelve thousand, two hundred forty".