129628026 has 120 divisors (see below), whose sum is σ = 338918580. Its totient is φ = 36875520.

The previous prime is 129628007. The next prime is 129628027. The reversal of 129628026 is 620826921.

It is a happy number.

129628026 is a `hidden beast` number, since 1 + 2 + 9 + 628 + 0 + 26 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 129618225 + 9801 = 11385^2 + 99^2 .

It is not an unprimeable number, because it can be changed into a prime (129628027) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 333040 + ... + 333428.

Almost surely, 2^129628026 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129628026, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (169459290).

129628026 is an abundant number, since it is smaller than the sum of its proper divisors (209290554).

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

129628026 is a wasteful number, since it uses less digits than its factorization.

129628026 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442 (or 422 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The square root of 129628026 is about 11385.4304266462. The cubic root of 129628026 is about 506.0960750147.

The spelling of 129628026 in words is "one hundred twenty-nine million, six hundred twenty-eight thousand, twenty-six".