20001021210979 has 2 divisors, whose sum is σ = 20001021210980. Its totient is φ = 20001021210978.

The previous prime is 20001021210971. The next prime is 20001021210991. The reversal of 20001021210979 is 97901212010002.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20001021210979 - 2³ = 20001021210971 is a prime.

It is not a weakly prime, because it can be changed into another prime (20001021210971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10000510605489 + 10000510605490.

It is an arithmetic number, because the mean of its divisors is an integer number (10000510605490).

Almost surely, 2^{20001021210979} is an apocalyptic number.

20001021210979 is a deficient number, since it is larger than the sum of its proper divisors (1).

20001021210979 is an equidigital number, since it uses as much as digits as its factorization.

20001021210979 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 20001021210979 in words is "twenty trillion, one billion, twenty-one million, two hundred ten thousand, nine hundred seventy-nine".