21438717874711 has 4 divisors (see below), whose sum is σ = 21438984781672. Its totient is φ = 21438450967752.

The previous prime is 21438717874709. The next prime is 21438717874751. The reversal of 21438717874711 is 11747871783412.

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

It is a cyclic number.

It is not a de Polignac number, because 21438717874711 - 2¹ = 21438717874709 is a prime.

It is a super-2 number, since 2×21438717874711² (a number of 27 digits) contains 22 as substring.

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 21438717874711.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21438717874751) 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, 133332960 + ... + 133493653.

It is an arithmetic number, because the mean of its divisors is an integer number (5359746195418).

Almost surely, 2^{21438717874711} is an apocalyptic number.

21438717874711 is a deficient number, since it is larger than the sum of its proper divisors (266906961).

21438717874711 is an equidigital number, since it uses as much as digits as its factorization.

21438717874711 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 266906960.

The product of its digits is 14751744, while the sum is 61.

The spelling of 21438717874711 in words is "twenty-one trillion, four hundred thirty-eight billion, seven hundred seventeen million, eight hundred seventy-four thousand, seven hundred eleven".