129172950 has 72 divisors (see below), whose sum is σ = 349526736. Its totient is φ = 34200000.

The previous prime is 129172933. The next prime is 129172951. The reversal of 129172950 is 59271921.

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129172951) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 67000 + ... + 68900.

It is an arithmetic number, because the mean of its divisors is an integer number (4854538).

Almost surely, 2^129172950 is an apocalyptic number.

129172950 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 129172950, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (174763368).

129172950 is an abundant number, since it is smaller than the sum of its proper divisors (220353786).

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

129172950 is a wasteful number, since it uses less digits than its factorization.

129172950 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2070 (or 2062 counting only the distinct ones).

The product of its (nonzero) digits is 11340, while the sum is 36.

The square root of 129172950 is about 11365.4278406050. The cubic root of 129172950 is about 505.5031419764.

The spelling of 129172950 in words is "one hundred twenty-nine million, one hundred seventy-two thousand, nine hundred fifty".