21291178476993 has 16 divisors (see below), whose sum is σ = 28537281856512. Its totient is φ = 14119599200000.

The previous prime is 21291178476991. The next prime is 21291178477027. The reversal of 21291178476993 is 39967487119212.

It is a cyclic number.

It is not a de Polignac number, because 21291178476993 - 2¹ = 21291178476991 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21291178476991) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 46207243 + ... + 46665743.

It is an arithmetic number, because the mean of its divisors is an integer number (1783580116032).

Almost surely, 2^{21291178476993} is an apocalyptic number.

It is an amenable number.

21291178476993 is a deficient number, since it is larger than the sum of its proper divisors (7246103379519).

21291178476993 is a wasteful number, since it uses less digits than its factorization.

21291178476993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 539736.

The product of its digits is 82301184, while the sum is 69.

The spelling of 21291178476993 in words is "twenty-one trillion, two hundred ninety-one billion, one hundred seventy-eight million, four hundred seventy-six thousand, nine hundred ninety-three".