129691438 has 16 divisors (see below), whose sum is σ = 200658240. Its totient is φ = 62820576.

The previous prime is 129691421. The next prime is 129691447. The reversal of 129691438 is 834196921.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 129691394 and 129691403.

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 in 7 ways as a sum of consecutive naturals, for example, 14020 + ... + 21352.

It is an arithmetic number, because the mean of its divisors is an integer number (12541140).

Almost surely, 2^129691438 is an apocalyptic number.

129691438 is a deficient number, since it is larger than the sum of its proper divisors (70966802).

129691438 is a wasteful number, since it uses less digits than its factorization.

129691438 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7611.

The product of its digits is 93312, while the sum is 43.

The square root of 129691438 is about 11388.2148732802. The cubic root of 129691438 is about 506.1785863194.

The spelling of 129691438 in words is "one hundred twenty-nine million, six hundred ninety-one thousand, four hundred thirty-eight".