102191899 has 4 divisors (see below), whose sum is σ = 107570440. Its totient is φ = 96813360.

The previous prime is 102191867. The next prime is 102191909. The reversal of 102191899 is 998191201.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 102191899 - 2⁵ = 102191867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (102191839) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2689242 + ... + 2689279.

It is an arithmetic number, because the mean of its divisors is an integer number (26892610).

Almost surely, 2^102191899 is an apocalyptic number.

102191899 is a gapful number since it is divisible by the number (19) formed by its first and last digit.

102191899 is a deficient number, since it is larger than the sum of its proper divisors (5378541).

102191899 is an equidigital number, since it uses as much as digits as its factorization.

102191899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5378540.

The product of its (nonzero) digits is 11664, while the sum is 40.

The square root of 102191899 is about 10109.0008902957. Note that the first 3 decimals coincide. The cubic root of 102191899 is about 467.5257007804.

The spelling of 102191899 in words is "one hundred two million, one hundred ninety-one thousand, eight hundred ninety-nine".