21171190423679 has 4 divisors (see below), whose sum is σ = 21174087022920. Its totient is φ = 21168293824440.

The previous prime is 21171190423661. The next prime is 21171190423723. The reversal of 21171190423679 is 97632409117112.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21171190423679 is a prime.

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 21171190423679.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21171190426679) 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, 1448288657 + ... + 1448303274.

It is an arithmetic number, because the mean of its divisors is an integer number (5293521755730).

Almost surely, 2^{21171190423679} is an apocalyptic number.

21171190423679 is a deficient number, since it is larger than the sum of its proper divisors (2896599241).

21171190423679 is an equidigital number, since it uses as much as digits as its factorization.

21171190423679 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2896599240.

The product of its (nonzero) digits is 1143072, while the sum is 53.

The spelling of 21171190423679 in words is "twenty-one trillion, one hundred seventy-one billion, one hundred ninety million, four hundred twenty-three thousand, six hundred seventy-nine".