21513540334555 has 4 divisors (see below), whose sum is σ = 25816248401472. Its totient is φ = 17210832267640.

The previous prime is 21513540334549. The next prime is 21513540334651. The reversal of 21513540334555 is 55543304531512.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 21513540334555 - 2³³ = 21504950399963 is a prime.

It is a super-2 number, since 2×21513540334555² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2151354033451 + ... + 2151354033460.

It is an arithmetic number, because the mean of its divisors is an integer number (6454062100368).

Almost surely, 2^{21513540334555} is an apocalyptic number.

21513540334555 is a deficient number, since it is larger than the sum of its proper divisors (4302708066917).

21513540334555 is an equidigital number, since it uses as much as digits as its factorization.

21513540334555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4302708066916.

The product of its (nonzero) digits is 2700000, while the sum is 46.

The spelling of 21513540334555 in words is "twenty-one trillion, five hundred thirteen billion, five hundred forty million, three hundred thirty-four thousand, five hundred fifty-five".