21035334540 has 288 divisors, whose sum is σ = 70237202112. Its totient is φ = 4681318400.

The previous prime is 21035334533. The next prime is 21035334569. The reversal of 21035334540 is 4543353012.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 21035334498 and 21035334507.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 5058142 + ... + 5062298.

It is an arithmetic number, because the mean of its divisors is an integer number (243879174).

Almost surely, 2^21035334540 is an apocalyptic number.

21035334540 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 21035334540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35118601056).

21035334540 is an abundant number, since it is smaller than the sum of its proper divisors (49201867572).

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

21035334540 is a wasteful number, since it uses less digits than its factorization.

21035334540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4249 (or 4236 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 30.

Adding to 21035334540 its reverse (4543353012), we get a palindrome (25578687552).

The spelling of 21035334540 in words is "twenty-one billion, thirty-five million, three hundred thirty-four thousand, five hundred forty".