21261012546353 has 4 divisors (see below), whose sum is σ = 21261631226880. Its totient is φ = 21260393865828.

The previous prime is 21261012546341. The next prime is 21261012546359. The reversal of 21261012546353 is 35364521016212.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21261012546353 - 2²⁰ = 21261011497777 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21261012546353.

It is not an unprimeable number, because it can be changed into a prime (21261012546359) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 309288713 + ... + 309357446.

It is an arithmetic number, because the mean of its divisors is an integer number (5315407806720).

Almost surely, 2^{21261012546353} is an apocalyptic number.

It is an amenable number.

21261012546353 is a deficient number, since it is larger than the sum of its proper divisors (618680527).

21261012546353 is an equidigital number, since it uses as much as digits as its factorization.

21261012546353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 618680526.

The product of its (nonzero) digits is 259200, while the sum is 41.

The spelling of 21261012546353 in words is "twenty-one trillion, two hundred sixty-one billion, twelve million, five hundred forty-six thousand, three hundred fifty-three".