21330413555 has 64 divisors (see below), whose sum is σ = 30736972800. Its totient is φ = 14027397120.

The previous prime is 21330413551. The next prime is 21330413569. The reversal of 21330413555 is 55531403312.

It is not a de Polignac number, because 21330413555 - 2² = 21330413551 is a prime.

It is a super-3 number, since 3×21330413555³ (a number of 32 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (21330413551) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 19443767 + ... + 19444863.

It is an arithmetic number, because the mean of its divisors is an integer number (480265200).

Almost surely, 2^21330413555 is an apocalyptic number.

21330413555 is a deficient number, since it is larger than the sum of its proper divisors (9406559245).

21330413555 is a wasteful number, since it uses less digits than its factorization.

21330413555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1964.

The product of its (nonzero) digits is 27000, while the sum is 32.

Adding to 21330413555 its reverse (55531403312), we get a palindrome (76861816867).

The spelling of 21330413555 in words is "twenty-one billion, three hundred thirty million, four hundred thirteen thousand, five hundred fifty-five".