21260566106553 has 4 divisors (see below), whose sum is σ = 28347421475408. Its totient is φ = 14173710737700.

The previous prime is 21260566106513. The next prime is 21260566106561. The reversal of 21260566106553 is 35560166506212.

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 not a de Polignac number, because 21260566106553 - 2³³ = 21251976171961 is a prime.

It is a super-2 number, since 2×21260566106553² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21260566106513) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3543427684423 + ... + 3543427684428.

It is an arithmetic number, because the mean of its divisors is an integer number (7086855368852).

Almost surely, 2^{21260566106553} is an apocalyptic number.

It is an amenable number.

21260566106553 is a deficient number, since it is larger than the sum of its proper divisors (7086855368855).

21260566106553 is an equidigital number, since it uses as much as digits as its factorization.

21260566106553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7086855368854.

The product of its (nonzero) digits is 1944000, while the sum is 48.

The spelling of 21260566106553 in words is "twenty-one trillion, two hundred sixty billion, five hundred sixty-six million, one hundred six thousand, five hundred fifty-three".