129021312 has 96 divisors (see below), whose sum is σ = 398724120. Its totient is φ = 36857856.

The previous prime is 129021293. The next prime is 129021317. The reversal of 129021312 is 213120921.

It is a tau number, because it is divible by the number of its divisors (96).

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129021317) 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, 15388 + ... + 22244.

Almost surely, 2^129021312 is an apocalyptic number.

129021312 is a gapful number since it is divisible by the number (12) 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 129021312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (199362060).

129021312 is an abundant number, since it is smaller than the sum of its proper divisors (269702808).

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

129021312 is an equidigital number, since it uses as much as digits as its factorization.

129021312 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6888 (or 6869 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 21.

The square root of 129021312 is about 11358.7548613393. The cubic root of 129021312 is about 505.3052586995.

The spelling of 129021312 in words is "one hundred twenty-nine million, twenty-one thousand, three hundred twelve".