102009191 has 4 divisors (see below), whose sum is σ = 102522000. Its totient is φ = 101496384.

The previous prime is 102009169. The next prime is 102009217. The reversal of 102009191 is 191900201.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-102009191 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (102000191) 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, 256106 + ... + 256503.

It is an arithmetic number, because the mean of its divisors is an integer number (25630500).

Almost surely, 2^102009191 is an apocalyptic number.

102009191 is a deficient number, since it is larger than the sum of its proper divisors (512809).

102009191 is an equidigital number, since it uses as much as digits as its factorization.

102009191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 512808.

The product of its (nonzero) digits is 162, while the sum is 23.

The square root of 102009191 is about 10099.9599504156. The cubic root of 102009191 is about 467.2469061962.

Adding to 102009191 its reverse (191900201), we get a palindrome (293909392).

It can be divided in two parts, 10200 and 9191, that added together give a palindrome (19391).

The spelling of 102009191 in words is "one hundred two million, nine thousand, one hundred ninety-one".