129016639 has 4 divisors (see below), whose sum is σ = 129054640. Its totient is φ = 128978640.

The previous prime is 129016579. The next prime is 129016649. The reversal of 129016639 is 936610921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 936610921 = 1097 ⋅853793.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129016639 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 129016598 and 129016607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129016649) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13347 + ... + 20884.

It is an arithmetic number, because the mean of its divisors is an integer number (32263660).

Almost surely, 2^129016639 is an apocalyptic number.

129016639 is a deficient number, since it is larger than the sum of its proper divisors (38001).

129016639 is an equidigital number, since it uses as much as digits as its factorization.

129016639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38000.

The product of its (nonzero) digits is 17496, while the sum is 37.

The square root of 129016639 is about 11358.5491591136. The cubic root of 129016639 is about 505.2991581053.

The spelling of 129016639 in words is "one hundred twenty-nine million, sixteen thousand, six hundred thirty-nine".