129227729 has 4 divisors (see below), whose sum is σ = 129308784. Its totient is φ = 129146676.

The previous prime is 129227719. The next prime is 129227737. The reversal of 129227729 is 927722921.

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, and also an emirpimes, since its reverse is a distinct semiprime: 927722921 = 181 ⋅5125541.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129227729 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129227719) 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, 38087 + ... + 41340.

It is an arithmetic number, because the mean of its divisors is an integer number (32327196).

Almost surely, 2^129227729 is an apocalyptic number.

It is an amenable number.

129227729 is a deficient number, since it is larger than the sum of its proper divisors (81055).

129227729 is an equidigital number, since it uses as much as digits as its factorization.

129227729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 81054.

The product of its digits is 63504, while the sum is 41.

The square root of 129227729 is about 11367.8374812451. The cubic root of 129227729 is about 505.5745889349.

The spelling of 129227729 in words is "one hundred twenty-nine million, two hundred twenty-seven thousand, seven hundred twenty-nine".