21201222021979 has 2 divisors, whose sum is σ = 21201222021980. Its totient is φ = 21201222021978.

The previous prime is 21201222021977. The next prime is 21201222022051. The reversal of 21201222021979 is 97912022210212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21201222021979 - 2¹ = 21201222021977 is a prime.

Together with 21201222021977, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (21201222021971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10600611010989 + 10600611010990.

It is an arithmetic number, because the mean of its divisors is an integer number (10600611010990).

Almost surely, 2^{21201222021979} is an apocalyptic number.

21201222021979 is a deficient number, since it is larger than the sum of its proper divisors (1).

21201222021979 is an equidigital number, since it uses as much as digits as its factorization.

21201222021979 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 36288, while the sum is 40.

The spelling of 21201222021979 in words is "twenty-one trillion, two hundred one billion, two hundred twenty-two million, twenty-one thousand, nine hundred seventy-nine".