21768368405731 has 4 divisors (see below), whose sum is σ = 21768902626464. Its totient is φ = 21767834185000.

The previous prime is 21768368405711. The next prime is 21768368405753. The reversal of 21768368405731 is 13750486386712.

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 21768368405731 - 2¹⁹ = 21768367881443 is a prime.

It is a super-2 number, since 2×21768368405731² (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 21768368405731.

It is not an unprimeable number, because it can be changed into a prime (21768368405711) 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, 267049240 + ... + 267130741.

It is an arithmetic number, because the mean of its divisors is an integer number (5442225656616).

Almost surely, 2^{21768368405731} is an apocalyptic number.

21768368405731 is a deficient number, since it is larger than the sum of its proper divisors (534220733).

21768368405731 is an equidigital number, since it uses as much as digits as its factorization.

21768368405731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 534220732.

The product of its (nonzero) digits is 40642560, while the sum is 61.

The spelling of 21768368405731 in words is "twenty-one trillion, seven hundred sixty-eight billion, three hundred sixty-eight million, four hundred five thousand, seven hundred thirty-one".