129228768 has 72 divisors (see below), whose sum is σ = 368608968. Its totient is φ = 42945792.

The previous prime is 129228763. The next prime is 129228773. The reversal of 129228768 is 867822921.

It is an interprime number because it is at equal distance from previous prime (129228763) and next prime (129228773).

It is a tau number, because it is divible by the number of its divisors (72).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129228763) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 161746 + ... + 162542.

It is an arithmetic number, because the mean of its divisors is an integer number (5119569).

Almost surely, 2^129228768 is an apocalyptic number.

129228768 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129228768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (184304484).

129228768 is an abundant number, since it is smaller than the sum of its proper divisors (239380200).

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

129228768 is a wasteful number, since it uses less digits than its factorization.

129228768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1376 (or 1365 counting only the distinct ones).

The product of its digits is 193536, while the sum is 45.

The square root of 129228768 is about 11367.8831802583. The cubic root of 129228768 is about 505.5759438830.

The spelling of 129228768 in words is "one hundred twenty-nine million, two hundred twenty-eight thousand, seven hundred sixty-eight".