2000123121991 has 2 divisors, whose sum is σ = 2000123121992. Its totient is φ = 2000123121990.

The previous prime is 2000123121977. The next prime is 2000123122007. The reversal of 2000123121991 is 1991213210002.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2000123121991 - 2⁷ = 2000123121863 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2000123121091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1000061560995 + 1000061560996.

It is an arithmetic number, because the mean of its divisors is an integer number (1000061560996).

Almost surely, 2^{2000123121991} is an apocalyptic number.

2000123121991 is a deficient number, since it is larger than the sum of its proper divisors (1).

2000123121991 is an equidigital number, since it uses as much as digits as its factorization.

2000123121991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1944, while the sum is 31.

Adding to 2000123121991 its reverse (1991213210002), we get a palindrome (3991336331993).

The spelling of 2000123121991 in words is "two trillion, one hundred twenty-three million, one hundred twenty-one thousand, nine hundred ninety-one".