129105550 has 24 divisors (see below), whose sum is σ = 274442256. Its totient is φ = 44264640.

The previous prime is 129105539. The next prime is 129105623. The reversal of 129105550 is 55501921.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 184087 + ... + 184786.

It is an arithmetic number, because the mean of its divisors is an integer number (11435094).

Almost surely, 2^129105550 is an apocalyptic number.

129105550 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

129105550 is an abundant number, since it is smaller than the sum of its proper divisors (145336706).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

129105550 is a wasteful number, since it uses less digits than its factorization.

129105550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 368892 (or 368887 counting only the distinct ones).

The product of its (nonzero) digits is 2250, while the sum is 28.

The square root of 129105550 is about 11362.4623211697. The cubic root of 129105550 is about 505.4152060235.

The spelling of 129105550 in words is "one hundred twenty-nine million, one hundred five thousand, five hundred fifty".