129251916 has 48 divisors (see below), whose sum is σ = 339158400. Its totient is φ = 42561936.

The previous prime is 129251887. The next prime is 129251921. The reversal of 129251916 is 619152921.

129251916 is a `hidden beast` number, since 129 + 2 + 519 + 16 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1755 + ... + 16173.

It is an arithmetic number, because the mean of its divisors is an integer number (7065800).

Almost surely, 2^129251916 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 129251916, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169579200).

129251916 is an abundant number, since it is smaller than the sum of its proper divisors (209906484).

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

129251916 is a wasteful number, since it uses less digits than its factorization.

129251916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14515 (or 14507 counting only the distinct ones).

The product of its digits is 9720, while the sum is 36.

The square root of 129251916 is about 11368.9012661734. The cubic root of 129251916 is about 505.6061290433.

It can be divided in two parts, 12925 and 1916, that added together give a palindrome (14841).

The spelling of 129251916 in words is "one hundred twenty-nine million, two hundred fifty-one thousand, nine hundred sixteen".