129939280 has 20 divisors (see below), whose sum is σ = 302109012. Its totient is φ = 51975680.

The previous prime is 129939263. The next prime is 129939283. The reversal of 129939280 is 82939921.

It can be written as a sum of positive squares in 2 ways, for example, as 23931664 + 106007616 = 4892^2 + 10296^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129939283) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 812041 + ... + 812200.

Almost surely, 2^129939280 is an apocalyptic number.

129939280 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

129939280 is an abundant number, since it is smaller than the sum of its proper divisors (172169732).

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

129939280 is a wasteful number, since it uses less digits than its factorization.

129939280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1624254 (or 1624248 counting only the distinct ones).

The product of its (nonzero) digits is 69984, while the sum is 43.

The square root of 129939280 is about 11399.0911918451. The cubic root of 129939280 is about 506.5008190645.

The spelling of 129939280 in words is "one hundred twenty-nine million, nine hundred thirty-nine thousand, two hundred eighty".