129220056 has 192 divisors, whose sum is σ = 432972000. Its totient is φ = 35562240.

The previous prime is 129220033. The next prime is 129220057. The reversal of 129220056 is 650022921.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129220057) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 306726 + ... + 307146.

Almost surely, 2^129220056 is an apocalyptic number.

It is a pronic number, being equal to 11367×11368.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129220056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (216486000).

129220056 is an abundant number, since it is smaller than the sum of its proper divisors (303751944).

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

129220056 is a wasteful number, since it uses less digits than its factorization.

129220056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479 (or 462 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 129220056 is about 11367.4999890037. The cubic root of 129220056 is about 505.5645824380.

Adding to 129220056 its reverse (650022921), we get a palindrome (779242977).

The spelling of 129220056 in words is "one hundred twenty-nine million, two hundred twenty thousand, fifty-six".