21202102111979 has 2 divisors, whose sum is σ = 21202102111980. Its totient is φ = 21202102111978.

The previous prime is 21202102111973. The next prime is 21202102112041. The reversal of 21202102111979 is 97911120120212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21202102111979 - 2⁴ = 21202102111963 is a prime.

It is not a weakly prime, because it can be changed into another prime (21202102111973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10601051055989 + 10601051055990.

It is an arithmetic number, because the mean of its divisors is an integer number (10601051055990).

Almost surely, 2^{21202102111979} is an apocalyptic number.

21202102111979 is a deficient number, since it is larger than the sum of its proper divisors (1).

21202102111979 is an equidigital number, since it uses as much as digits as its factorization.

21202102111979 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 38.

The spelling of 21202102111979 in words is "twenty-one trillion, two hundred two billion, one hundred two million, one hundred eleven thousand, nine hundred seventy-nine".