129987919 has 6 divisors (see below), whose sum is σ = 133597464. Its totient is φ = 126473400.

The previous prime is 129987901. The next prime is 129987941. The reversal of 129987919 is 919789921.

It is not a de Polignac number, because 129987919 - 2⁵ = 129987887 is a prime.

It is a super-2 number, since 2×129987919² = 33793718171901122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 129987919.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129987119) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 46107 + ... + 48844.

It is an arithmetic number, because the mean of its divisors is an integer number (22266244).

Almost surely, 2^129987919 is an apocalyptic number.

129987919 is the 6583-rd hex number.

129987919 is a deficient number, since it is larger than the sum of its proper divisors (3609545).

129987919 is an frugal number, since it uses more digits than its factorization.

129987919 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95025 (or 94988 counting only the distinct ones).

The product of its digits is 734832, while the sum is 55.

The square root of 129987919 is about 11401.2244517859. The cubic root of 129987919 is about 506.5640091435.

The spelling of 129987919 in words is "one hundred twenty-nine million, nine hundred eighty-seven thousand, nine hundred nineteen".