21220121223179 has 2 divisors, whose sum is σ = 21220121223180. Its totient is φ = 21220121223178.

The previous prime is 21220121223109. The next prime is 21220121223251. The reversal of 21220121223179 is 97132212102212.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21220121223179 is a prime.

It is not a weakly prime, because it can be changed into another prime (21220121223109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610060611589 + 10610060611590.

It is an arithmetic number, because the mean of its divisors is an integer number (10610060611590).

Almost surely, 2^{21220121223179} is an apocalyptic number.

21220121223179 is a deficient number, since it is larger than the sum of its proper divisors (1).

21220121223179 is an equidigital number, since it uses as much as digits as its factorization.

21220121223179 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 35.

The spelling of 21220121223179 in words is "twenty-one trillion, two hundred twenty billion, one hundred twenty-one million, two hundred twenty-three thousand, one hundred seventy-nine".