102120210991 has 2 divisors, whose sum is σ = 102120210992. Its totient is φ = 102120210990.

The previous prime is 102120210889. The next prime is 102120211013. The reversal of 102120210991 is 199012021201.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 102120210991 - 2¹³ = 102120202799 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102120213991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51060105495 + 51060105496.

It is an arithmetic number, because the mean of its divisors is an integer number (51060105496).

Almost surely, 2^102120210991 is an apocalyptic number.

102120210991 is a deficient number, since it is larger than the sum of its proper divisors (1).

102120210991 is an equidigital number, since it uses as much as digits as its factorization.

102120210991 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 28.

It can be divided in two parts, 102120210 and 991, that added together give a palindrome (102121201).

The spelling of 102120210991 in words is "one hundred two billion, one hundred twenty million, two hundred ten thousand, nine hundred ninety-one".