129640155 has 32 divisors (see below), whose sum is σ = 213530688. Its totient is φ = 67123200.

The previous prime is 129640153. The next prime is 129640163. The reversal of 129640155 is 551046921.

It is not a de Polignac number, because 129640155 - 2¹ = 129640153 is a prime.

It is not an unprimeable number, because it can be changed into a prime (129640153) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 169975 + ... + 170735.

It is an arithmetic number, because the mean of its divisors is an integer number (6672834).

Almost surely, 2^129640155 is an apocalyptic number.

129640155 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

129640155 is a deficient number, since it is larger than the sum of its proper divisors (83890533).

129640155 is a wasteful number, since it uses less digits than its factorization.

129640155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1087.

The product of its (nonzero) digits is 10800, while the sum is 33.

The square root of 129640155 is about 11385.9630686209. The cubic root of 129640155 is about 506.1118592758. Note that the first 3 decimals are identical.

It can be divided in two parts, 129640 and 155, that added together give a triangular number (129795 = T₅₀₉).

The spelling of 129640155 in words is "one hundred twenty-nine million, six hundred forty thousand, one hundred fifty-five".