129868816 has 135 divisors (see below), whose sum is σ = 330660477. Its totient is φ = 49230720.

The previous prime is 129868799. The next prime is 129868829. The reversal of 129868816 is 618868921.

The square root of 129868816 is 11396.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 116208400 + 13660416 = 10780^2 + 3696^2 .

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a self number, because there is not a number n which added to its sum of digits gives 129868816.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 3509950 + ... + 3509986.

Almost surely, 2^129868816 is an apocalyptic number.

129868816 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

129868816 is the 11396-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129868816

129868816 is an abundant number, since it is smaller than the sum of its proper divisors (200791661).

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

129868816 is a wasteful number, since it uses less digits than its factorization.

129868816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118 (or 57 counting only the distinct ones).

The product of its digits is 331776, while the sum is 49.

The cubic root of 129868816 is about 506.4092467367.

Multiplying 129868816 by its sum of digits (49), we get a square (6363571984 = 79772²).

129868816 divided by its sum of digits (49) gives a square (2650384 = 1628²).

Multiplying 129868816 by its product of digits (331776), we get a square (43087356297216 = 6564096²).

The spelling of 129868816 in words is "one hundred twenty-nine million, eight hundred sixty-eight thousand, eight hundred sixteen".