129871965 has 16 divisors (see below), whose sum is σ = 209000448. Its totient is φ = 68863296.

The previous prime is 129871949. The next prime is 129871967. The reversal of 129871965 is 569178921.

It is not a de Polignac number, because 129871965 - 2⁴ = 129871949 is a prime.

It is a super-2 number, since 2×129871965² = 33733454585922450, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129871967) 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 15 ways as a sum of consecutive naturals, for example, 22429 + ... + 27618.

It is an arithmetic number, because the mean of its divisors is an integer number (13062528).

Almost surely, 2^129871965 is an apocalyptic number.

129871965 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

129871965 is a deficient number, since it is larger than the sum of its proper divisors (79128483).

129871965 is a wasteful number, since it uses less digits than its factorization.

129871965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50228.

The product of its digits is 272160, while the sum is 48.

The square root of 129871965 is about 11396.1381616756. The cubic root of 129871965 is about 506.4133397640.

The spelling of 129871965 in words is "one hundred twenty-nine million, eight hundred seventy-one thousand, nine hundred sixty-five".