20210020111979 has 2 divisors, whose sum is σ = 20210020111980. Its totient is φ = 20210020111978.

The previous prime is 20210020111951. The next prime is 20210020112039. The reversal of 20210020111979 is 97911102001202.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20210020111979 is a prime.

It is not a weakly prime, because it can be changed into another prime (20210020111079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10105010055989 + 10105010055990.

It is an arithmetic number, because the mean of its divisors is an integer number (10105010055990).

Almost surely, 2^{20210020111979} is an apocalyptic number.

20210020111979 is a deficient number, since it is larger than the sum of its proper divisors (1).

20210020111979 is an equidigital number, since it uses as much as digits as its factorization.

20210020111979 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4536, while the sum is 35.

The spelling of 20210020111979 in words is "twenty trillion, two hundred ten billion, twenty million, one hundred eleven thousand, nine hundred seventy-nine".