21103240340 has 192 divisors, whose sum is σ = 58068057600. Its totient is φ = 6255304704.

The previous prime is 21103240337. The next prime is 21103240349. The reversal of 21103240340 is 4304230112.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21103240349) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 3074192 + ... + 3081048.

It is an arithmetic number, because the mean of its divisors is an integer number (302437800).

Almost surely, 2^21103240340 is an apocalyptic number.

21103240340 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21103240340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29034028800).

21103240340 is an abundant number, since it is smaller than the sum of its proper divisors (36964817260).

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

21103240340 is a wasteful number, since it uses less digits than its factorization.

21103240340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6994 (or 6992 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 20.

Adding to 21103240340 its reverse (4304230112), we get a palindrome (25407470452).

The spelling of 21103240340 in words is "twenty-one billion, one hundred three million, two hundred forty thousand, three hundred forty".