129316421 has 4 divisors (see below), whose sum is σ = 139263852. Its totient is φ = 119368992.

The previous prime is 129316387. The next prime is 129316427. The reversal of 129316421 is 124613921.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 9523396 + 119793025 = 3086^2 + 10945^2 .

It is a cyclic number.

It is not a de Polignac number, because 129316421 - 2⁶ = 129316357 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129316427) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4973696 + ... + 4973721.

It is an arithmetic number, because the mean of its divisors is an integer number (34815963).

Almost surely, 2^129316421 is an apocalyptic number.

It is an amenable number.

129316421 is a deficient number, since it is larger than the sum of its proper divisors (9947431).

129316421 is an equidigital number, since it uses as much as digits as its factorization.

129316421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9947430.

The product of its digits is 2592, while the sum is 29.

The square root of 129316421 is about 11371.7378179415. The cubic root of 129316421 is about 505.6902250226.

The spelling of 129316421 in words is "one hundred twenty-nine million, three hundred sixteen thousand, four hundred twenty-one".