129976394 has 4 divisors (see below), whose sum is σ = 194964594. Its totient is φ = 64988196.

The previous prime is 129976391. The next prime is 129976403. The reversal of 129976394 is 493679921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 493679921 = 7 ⋅70525703.

It can be written as a sum of positive squares in only one way, i.e., 80766169 + 49210225 = 8987^2 + 7015^2 .

It is not an unprimeable number, because it can be changed into a prime (129976391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32494097 + ... + 32494100.

Almost surely, 2^129976394 is an apocalyptic number.

129976394 is a deficient number, since it is larger than the sum of its proper divisors (64988200).

129976394 is an equidigital number, since it uses as much as digits as its factorization.

129976394 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64988199.

The product of its digits is 734832, while the sum is 50.

The square root of 129976394 is about 11400.7190124132. The cubic root of 129976394 is about 506.5490376939.

It can be divided in two parts, 12997 and 6394, that added together give a palindrome (19391).

The spelling of 129976394 in words is "one hundred twenty-nine million, nine hundred seventy-six thousand, three hundred ninety-four".