21333125540 has 24 divisors (see below), whose sum is σ = 46244712192. Its totient is φ = 8257983840.

The previous prime is 21333125507. The next prime is 21333125543. The reversal of 21333125540 is 4552133312.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (21333125543) by changing a digit.

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, 17203514 + ... + 17204753.

It is an arithmetic number, because the mean of its divisors is an integer number (1926863008).

Almost surely, 2^21333125540 is an apocalyptic number.

21333125540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21333125540 is an abundant number, since it is smaller than the sum of its proper divisors (24911586652).

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

21333125540 is a wasteful number, since it uses less digits than its factorization.

21333125540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34408307 (or 34408305 counting only the distinct ones).

The product of its (nonzero) digits is 10800, while the sum is 29.

Adding to 21333125540 its reverse (4552133312), we get a palindrome (25885258852).

The spelling of 21333125540 in words is "twenty-one billion, three hundred thirty-three million, one hundred twenty-five thousand, five hundred forty".