129521099 has 2 divisors, whose sum is σ = 129521100. Its totient is φ = 129521098.

The previous prime is 129521083. The next prime is 129521123. The reversal of 129521099 is 990125921.

It is a weak prime.

It is an emirp because it is prime and its reverse (990125921) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 129521099 - 2⁴ = 129521083 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (129524099) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64760549 + 64760550.

It is an arithmetic number, because the mean of its divisors is an integer number (64760550).

Almost surely, 2^129521099 is an apocalyptic number.

129521099 is a deficient number, since it is larger than the sum of its proper divisors (1).

129521099 is an equidigital number, since it uses as much as digits as its factorization.

129521099 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 14580, while the sum is 38.

The square root of 129521099 is about 11380.7336758225. The cubic root of 129521099 is about 505.9568812951.

The spelling of 129521099 in words is "one hundred twenty-nine million, five hundred twenty-one thousand, ninety-nine".