129431123 has 2 divisors, whose sum is σ = 129431124. Its totient is φ = 129431122.

The previous prime is 129431063. The next prime is 129431201. The reversal of 129431123 is 321134921.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 129431123 - 2¹⁰ = 129430099 is a prime.

It is a super-2 number, since 2×129431123² = 33504831202082258, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 129431092 and 129431101.

It is not a weakly prime, because it can be changed into another prime (129431623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64715561 + 64715562.

It is an arithmetic number, because the mean of its divisors is an integer number (64715562).

Almost surely, 2^129431123 is an apocalyptic number.

129431123 is a deficient number, since it is larger than the sum of its proper divisors (1).

129431123 is an equidigital number, since it uses as much as digits as its factorization.

129431123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1296, while the sum is 26.

The square root of 129431123 is about 11376.7799925990. The cubic root of 129431123 is about 505.8396944111.

The spelling of 129431123 in words is "one hundred twenty-nine million, four hundred thirty-one thousand, one hundred twenty-three".