20110121971 has 2 divisors, whose sum is σ = 20110121972. Its totient is φ = 20110121970.

The previous prime is 20110121963. The next prime is 20110122017. The reversal of 20110121971 is 17912101102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20110121971 - 2³ = 20110121963 is a prime.

It is not a weakly prime, because it can be changed into another prime (20110121371) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10055060985 + 10055060986.

It is an arithmetic number, because the mean of its divisors is an integer number (10055060986).

Almost surely, 2^20110121971 is an apocalyptic number.

20110121971 is a deficient number, since it is larger than the sum of its proper divisors (1).

20110121971 is an equidigital number, since it uses as much as digits as its factorization.

20110121971 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 252, while the sum is 25.

The spelling of 20110121971 in words is "twenty billion, one hundred ten million, one hundred twenty-one thousand, nine hundred seventy-one".