129981987 has 6 divisors (see below), whose sum is σ = 187751772. Its totient is φ = 86654652.

The previous prime is 129981961. The next prime is 129982001. The reversal of 129981987 is 789189921.

It is not a de Polignac number, because 129981987 - 2⁶ = 129981923 is a prime.

It is not an unprimeable number, because it can be changed into a prime (129981287) 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, 7221213 + ... + 7221230.

It is an arithmetic number, because the mean of its divisors is an integer number (31291962).

Almost surely, 2^129981987 is an apocalyptic number.

129981987 is a deficient number, since it is larger than the sum of its proper divisors (57769785).

129981987 is a wasteful number, since it uses less digits than its factorization.

129981987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14442449 (or 14442446 counting only the distinct ones).

The product of its digits is 653184, while the sum is 54.

The square root of 129981987 is about 11400.9643013212. The cubic root of 129981987 is about 506.5563033417.

The spelling of 129981987 in words is "one hundred twenty-nine million, nine hundred eighty-one thousand, nine hundred eighty-seven".