21210111009979 has 2 divisors, whose sum is σ = 21210111009980. Its totient is φ = 21210111009978.

The previous prime is 21210111009961. The next prime is 21210111010001. The reversal of 21210111009979 is 97990011101212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21210111009979 - 2⁷ = 21210111009851 is a prime.

It is not a weakly prime, because it can be changed into another prime (21210111709979) 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, 10605055504989 + 10605055504990.

It is an arithmetic number, because the mean of its divisors is an integer number (10605055504990).

Almost surely, 2^{21210111009979} is an apocalyptic number.

21210111009979 is a deficient number, since it is larger than the sum of its proper divisors (1).

21210111009979 is an equidigital number, since it uses as much as digits as its factorization.

21210111009979 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20412, while the sum is 43.

The spelling of 21210111009979 in words is "twenty-one trillion, two hundred ten billion, one hundred eleven million, nine thousand, nine hundred seventy-nine".