129408638 has 4 divisors (see below), whose sum is σ = 194112960. Its totient is φ = 64704318.

The previous prime is 129408619. The next prime is 129408659. The reversal of 129408638 is 836804921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 836804921 = 83 ⋅10081987.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 129408595 and 129408604.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32352158 + ... + 32352161.

It is an arithmetic number, because the mean of its divisors is an integer number (48528240).

Almost surely, 2^129408638 is an apocalyptic number.

129408638 is a deficient number, since it is larger than the sum of its proper divisors (64704322).

129408638 is an equidigital number, since it uses as much as digits as its factorization.

129408638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64704321.

The product of its (nonzero) digits is 82944, while the sum is 41.

The square root of 129408638 is about 11375.7917526650. The cubic root of 129408638 is about 505.8104009307.

The spelling of 129408638 in words is "one hundred twenty-nine million, four hundred eight thousand, six hundred thirty-eight".