21333404240 has 40 divisors (see below), whose sum is σ = 50753665248. Its totient is φ = 8334910080.

The previous prime is 21333404237. The next prime is 21333404243. The reversal of 21333404240 is 4240433312.

It is an interprime number because it is at equal distance from previous prime (21333404237) and next prime (21333404243).

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×21333404240² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21333404243) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3097346 + ... + 3104225.

Almost surely, 2^21333404240 is an apocalyptic number.

21333404240 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21333404240 is an abundant number, since it is smaller than the sum of its proper divisors (29420261008).

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

21333404240 is a wasteful number, since it uses less digits than its factorization.

21333404240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6201627 (or 6201621 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 26.

Adding to 21333404240 its reverse (4240433312), we get a palindrome (25573837552).

The spelling of 21333404240 in words is "twenty-one billion, three hundred thirty-three million, four hundred four thousand, two hundred forty".