102101221991 has 2 divisors, whose sum is σ = 102101221992. Its totient is φ = 102101221990.

The previous prime is 102101221951. The next prime is 102101222023. The reversal of 102101221991 is 199122101201.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 102101221991 - 2²⁶ = 102034113127 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (102101221951) 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, 51050610995 + 51050610996.

It is an arithmetic number, because the mean of its divisors is an integer number (51050610996).

Almost surely, 2^102101221991 is an apocalyptic number.

102101221991 is a deficient number, since it is larger than the sum of its proper divisors (1).

102101221991 is an equidigital number, since it uses as much as digits as its factorization.

102101221991 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 29.

The spelling of 102101221991 in words is "one hundred two billion, one hundred one million, two hundred twenty-one thousand, nine hundred ninety-one".