129217669 has 4 divisors (see below), whose sum is σ = 147677344. Its totient is φ = 110757996.

The previous prime is 129217667. The next prime is 129217687. The reversal of 129217669 is 966712921.

It is a happy number.

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 129217669 - 2¹ = 129217667 is a prime.

It is a super-2 number, since 2×129217669² = 33394411963587122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129217661) 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, 9229827 + ... + 9229840.

It is an arithmetic number, because the mean of its divisors is an integer number (36919336).

Almost surely, 2^129217669 is an apocalyptic number.

It is an amenable number.

129217669 is a deficient number, since it is larger than the sum of its proper divisors (18459675).

129217669 is an equidigital number, since it uses as much as digits as its factorization.

129217669 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18459674.

The product of its digits is 81648, while the sum is 43.

The square root of 129217669 is about 11367.3949962162. The cubic root of 129217669 is about 505.5614694277.

The spelling of 129217669 in words is "one hundred twenty-nine million, two hundred seventeen thousand, six hundred sixty-nine".