129940028 has 12 divisors (see below), whose sum is σ = 228757872. Its totient is φ = 64580640.

The previous prime is 129939991. The next prime is 129940043. The reversal of 129940028 is 820049921.

It is a self number, because there is not a number n which added to its sum of digits gives 129940028.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 96593 + ... + 97928.

It is an arithmetic number, because the mean of its divisors is an integer number (19063156).

Almost surely, 2^129940028 is an apocalyptic number.

It is an amenable number.

129940028 is a deficient number, since it is larger than the sum of its proper divisors (98817844).

129940028 is a wasteful number, since it uses less digits than its factorization.

129940028 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 194692 (or 194690 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 129940028 is about 11399.1240014310. The cubic root of 129940028 is about 506.5017909592.

Adding to 129940028 its reverse (820049921), we get a palindrome (949989949).

The spelling of 129940028 in words is "one hundred twenty-nine million, nine hundred forty thousand, twenty-eight".