21020010201979 has 2 divisors, whose sum is σ = 21020010201980. Its totient is φ = 21020010201978.

The previous prime is 21020010201973. The next prime is 21020010202007. The reversal of 21020010201979 is 97910201002012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21020010201979 - 2²⁵ = 21019976647547 is a prime.

It is not a weakly prime, because it can be changed into another prime (21020010201973) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510005100989 + 10510005100990.

It is an arithmetic number, because the mean of its divisors is an integer number (10510005100990).

Almost surely, 2^{21020010201979} is an apocalyptic number.

21020010201979 is a deficient number, since it is larger than the sum of its proper divisors (1).

21020010201979 is an equidigital number, since it uses as much as digits as its factorization.

21020010201979 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4536, while the sum is 34.

The spelling of 21020010201979 in words is "twenty-one trillion, twenty billion, ten million, two hundred one thousand, nine hundred seventy-nine".