21455266517 has 8 divisors (see below), whose sum is σ = 22743680256. Its totient is φ = 20169779392.

The previous prime is 21455266513. The next prime is 21455266519. The reversal of 21455266517 is 71566255412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21455266517 - 2² = 21455266513 is a prime.

It is a super-2 number, since 2×21455266517² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21455266513) 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, 716543 + ... + 745884.

It is an arithmetic number, because the mean of its divisors is an integer number (2842960032).

Almost surely, 2^21455266517 is an apocalyptic number.

It is an amenable number.

21455266517 is a deficient number, since it is larger than the sum of its proper divisors (1288413739).

21455266517 is a wasteful number, since it uses less digits than its factorization.

21455266517 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1463307.

The product of its digits is 504000, while the sum is 44.

The spelling of 21455266517 in words is "twenty-one billion, four hundred fifty-five million, two hundred sixty-six thousand, five hundred seventeen".