129121424 has 20 divisors (see below), whose sum is σ = 250416636. Its totient is φ = 64497792.

The previous prime is 129121393. The next prime is 129121429. The reversal of 129121424 is 424121921.

It can be written as a sum of positive squares in 2 ways, for example, as 4129024 + 124992400 = 2032^2 + 11180^2 .

It is a junction number, because it is equal to n+sod(n) for n = 129121393 and 129121402.

It is not an unprimeable number, because it can be changed into a prime (129121429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16082 + ... + 22734.

Almost surely, 2^129121424 is an apocalyptic number.

It is an amenable number.

129121424 is a deficient number, since it is larger than the sum of its proper divisors (121295212).

129121424 is a wasteful number, since it uses less digits than its factorization.

129121424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7874 (or 7868 counting only the distinct ones).

The product of its digits is 1152, while the sum is 26.

The square root of 129121424 is about 11363.1608278683. The cubic root of 129121424 is about 505.4359193912.

The spelling of 129121424 in words is "one hundred twenty-nine million, one hundred twenty-one thousand, four hundred twenty-four".