102020109991 has 2 divisors, whose sum is σ = 102020109992. Its totient is φ = 102020109990.

The previous prime is 102020109973. The next prime is 102020110001. The reversal of 102020109991 is 199901020201.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 102020109991 - 2¹⁷ = 102019978919 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102020109941) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 51010054995 + 51010054996.

It is an arithmetic number, because the mean of its divisors is an integer number (51010054996).

Almost surely, 2^102020109991 is an apocalyptic number.

102020109991 is a deficient number, since it is larger than the sum of its proper divisors (1).

102020109991 is an equidigital number, since it uses as much as digits as its factorization.

102020109991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2916, while the sum is 34.

The spelling of 102020109991 in words is "one hundred two billion, twenty million, one hundred nine thousand, nine hundred ninety-one".