129388216 has 8 divisors (see below), whose sum is σ = 242602920. Its totient is φ = 64694104.

The previous prime is 129388213. The next prime is 129388219. The reversal of 129388216 is 612883921.

It is an interprime number because it is at equal distance from previous prime (129388213) and next prime (129388219).

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129388213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8086756 + ... + 8086771.

It is an arithmetic number, because the mean of its divisors is an integer number (30325365).

Almost surely, 2^129388216 is an apocalyptic number.

It is an amenable number.

129388216 is a deficient number, since it is larger than the sum of its proper divisors (113214704).

129388216 is a wasteful number, since it uses less digits than its factorization.

129388216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16173533 (or 16173529 counting only the distinct ones).

The product of its digits is 41472, while the sum is 40.

The square root of 129388216 is about 11374.8941093972. The cubic root of 129388216 is about 505.7837921880.

The spelling of 129388216 in words is "one hundred twenty-nine million, three hundred eighty-eight thousand, two hundred sixteen".