10122001991 has 2 divisors, whose sum is σ = 10122001992. Its totient is φ = 10122001990.

The previous prime is 10122001969. The next prime is 10122002017. The reversal of 10122001991 is 19910022101.

It is an a-pointer prime, because the next prime (10122002017) can be obtained adding 10122001991 to its sum of digits (26).

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-10122001991 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 10122001991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (10122001931) 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, 5061000995 + 5061000996.

It is an arithmetic number, because the mean of its divisors is an integer number (5061000996).

Almost surely, 2^10122001991 is an apocalyptic number.

10122001991 is a deficient number, since it is larger than the sum of its proper divisors (1).

10122001991 is an equidigital number, since it uses as much as digits as its factorization.

10122001991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 324, while the sum is 26.

The spelling of 10122001991 in words is "ten billion, one hundred twenty-two million, one thousand, nine hundred ninety-one".