102111010021991 has 2 divisors, whose sum is σ = 102111010021992. Its totient is φ = 102111010021990.

The previous prime is 102111010021963. The next prime is 102111010022003. The reversal of 102111010021991 is 199120010111201.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 102111010021991 - 2²⁶ = 102110942913127 is a prime.

It is a super-2 number, since 2×102111010021991² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102111010021921) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51055505010995 + 51055505010996.

It is an arithmetic number, because the mean of its divisors is an integer number (51055505010996).

Almost surely, 2^{102111010021991} is an apocalyptic number.

102111010021991 is a deficient number, since it is larger than the sum of its proper divisors (1).

102111010021991 is an equidigital number, since it uses as much as digits as its factorization.

102111010021991 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 29.

The spelling of 102111010021991 in words is "one hundred two trillion, one hundred eleven billion, ten million, twenty-one thousand, nine hundred ninety-one".