129220243 has 4 divisors (see below), whose sum is σ = 132712720. Its totient is φ = 125727768.

The previous prime is 129220219. The next prime is 129220253. The reversal of 129220243 is 342022921.

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

It is a cyclic number.

It is not a de Polignac number, because 129220243 - 2⁹ = 129219731 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129220253) 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, 1746183 + ... + 1746256.

It is an arithmetic number, because the mean of its divisors is an integer number (33178180).

Almost surely, 2^129220243 is an apocalyptic number.

129220243 is a deficient number, since it is larger than the sum of its proper divisors (3492477).

129220243 is an equidigital number, since it uses as much as digits as its factorization.

129220243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3492476.

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 129220243 is about 11367.5082142042. The cubic root of 129220243 is about 505.5648263128.

The spelling of 129220243 in words is "one hundred twenty-nine million, two hundred twenty thousand, two hundred forty-three".