129021516 has 72 divisors (see below), whose sum is σ = 360766224. Its totient is φ = 38620800.

The previous prime is 129021511. The next prime is 129021523. The reversal of 129021516 is 615120921.

129021516 is a `hidden beast` number, since 129 + 0 + 21 + 516 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 129021516.

It is not an unprimeable number, because it can be changed into a prime (129021511) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13591 + ... + 21041.

It is an arithmetic number, because the mean of its divisors is an integer number (5010642).

Almost surely, 2^129021516 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129021516, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (180383112).

129021516 is an abundant number, since it is smaller than the sum of its proper divisors (231744708).

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

129021516 is a wasteful number, since it uses less digits than its factorization.

129021516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7511 (or 7506 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 129021516 is about 11358.7638411933. The cubic root of 129021516 is about 505.3055250178.

The spelling of 129021516 in words is "one hundred twenty-nine million, twenty-one thousand, five hundred sixteen".