21121102340 has 48 divisors (see below), whose sum is σ = 47864554752. Its totient is φ = 7782500736.

The previous prime is 21121102339. The next prime is 21121102349. The reversal of 21121102340 is 4320112112.

It is a super-2 number, since 2×21121102340² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21121102349) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43217 + ... + 210023.

It is an arithmetic number, because the mean of its divisors is an integer number (997178224).

Almost surely, 2^21121102340 is an apocalyptic number.

21121102340 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 21121102340, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23932277376).

21121102340 is an abundant number, since it is smaller than the sum of its proper divisors (26743452412).

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

21121102340 is a wasteful number, since it uses less digits than its factorization.

21121102340 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 167316 (or 167314 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 17.

Adding to 21121102340 its reverse (4320112112), we get a palindrome (25441214452).

The spelling of 21121102340 in words is "twenty-one billion, one hundred twenty-one million, one hundred two thousand, three hundred forty".