129977409 has 4 divisors (see below), whose sum is σ = 173303216. Its totient is φ = 86651604.

The previous prime is 129977401. The next prime is 129977417. The reversal of 129977409 is 904779921.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (129977401) and next prime (129977417).

It is not a de Polignac number, because 129977409 - 2³ = 129977401 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (129977401) 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, 21662899 + ... + 21662904.

It is an arithmetic number, because the mean of its divisors is an integer number (43325804).

Almost surely, 2^129977409 is an apocalyptic number.

It is an amenable number.

129977409 is a deficient number, since it is larger than the sum of its proper divisors (43325807).

129977409 is an equidigital number, since it uses as much as digits as its factorization.

129977409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43325806.

The product of its (nonzero) digits is 285768, while the sum is 48.

The square root of 129977409 is about 11400.7635270626. The cubic root of 129977409 is about 506.5503562562.

The spelling of 129977409 in words is "one hundred twenty-nine million, nine hundred seventy-seven thousand, four hundred nine".