129189917 has 4 divisors (see below), whose sum is σ = 129866496. Its totient is φ = 128513340.

The previous prime is 129189889. The next prime is 129189923. The reversal of 129189917 is 719981921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 129189917 - 2¹⁰ = 129188893 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 (129189937) 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, 338003 + ... + 338384.

It is an arithmetic number, because the mean of its divisors is an integer number (32466624).

Almost surely, 2^129189917 is an apocalyptic number.

It is an amenable number.

129189917 is a deficient number, since it is larger than the sum of its proper divisors (676579).

129189917 is an equidigital number, since it uses as much as digits as its factorization.

129189917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 676578.

The product of its digits is 81648, while the sum is 47.

The square root of 129189917 is about 11366.1742464208. The cubic root of 129189917 is about 505.5252737935.

The spelling of 129189917 in words is "one hundred twenty-nine million, one hundred eighty-nine thousand, nine hundred seventeen".