129187028 has 6 divisors (see below), whose sum is σ = 226077306. Its totient is φ = 64593512.

The previous prime is 129186997. The next prime is 129187031. The reversal of 129187028 is 820781921.

It can be written as a sum of positive squares in only one way, i.e., 127193284 + 1993744 = 11278^2 + 1412^2 .

It is a junction number, because it is equal to n+sod(n) for n = 129186982 and 129187000.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16148375 + ... + 16148382.

It is an arithmetic number, because the mean of its divisors is an integer number (37679551).

Almost surely, 2^129187028 is an apocalyptic number.

It is an amenable number.

129187028 is a deficient number, since it is larger than the sum of its proper divisors (96890278).

129187028 is a wasteful number, since it uses less digits than its factorization.

129187028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32296761 (or 32296759 counting only the distinct ones).

The product of its (nonzero) digits is 16128, while the sum is 38.

The square root of 129187028 is about 11366.0471580933. The cubic root of 129187028 is about 505.5215055082.

The spelling of 129187028 in words is "one hundred twenty-nine million, one hundred eighty-seven thousand, twenty-eight".