21353341240 has 128 divisors (see below), whose sum is σ = 60332428800. Its totient is φ = 6607572480.

The previous prime is 21353341237. The next prime is 21353341253. The reversal of 21353341240 is 4214335312.

It is a happy number.

It is a super-2 number, since 2×21353341240² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a junction number, because it is equal to n+sod(n) for n = 21353341199 and 21353341208.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 403182 + ... + 453058.

It is an arithmetic number, because the mean of its divisors is an integer number (471347100).

Almost surely, 2^21353341240 is an apocalyptic number.

21353341240 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 21353341240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30166214400).

21353341240 is an abundant number, since it is smaller than the sum of its proper divisors (38979087560).

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

21353341240 is a wasteful number, since it uses less digits than its factorization.

21353341240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50045 (or 50041 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 28.

Adding to 21353341240 its reverse (4214335312), we get a palindrome (25567676552).

The spelling of 21353341240 in words is "twenty-one billion, three hundred fifty-three million, three hundred forty-one thousand, two hundred forty".