129505785 has 8 divisors (see below), whose sum is σ = 207209280. Its totient is φ = 69069744.

The previous prime is 129505781. The next prime is 129505787. The reversal of 129505785 is 587505921.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 129505785 - 2² = 129505781 is a prime.

It is not an unprimeable number, because it can be changed into a prime (129505781) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4316845 + ... + 4316874.

It is an arithmetic number, because the mean of its divisors is an integer number (25901160).

Almost surely, 2^129505785 is an apocalyptic number.

129505785 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

129505785 is a deficient number, since it is larger than the sum of its proper divisors (77703495).

129505785 is an equidigital number, since it uses as much as digits as its factorization.

129505785 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8633727.

The product of its (nonzero) digits is 126000, while the sum is 42.

The square root of 129505785 is about 11380.0608522099. The cubic root of 129505785 is about 505.9369398103.

The spelling of 129505785 in words is "one hundred twenty-nine million, five hundred five thousand, seven hundred eighty-five".