129959749 has 4 divisors (see below), whose sum is σ = 131790240. Its totient is φ = 128129260.

The previous prime is 129959741. The next prime is 129959761. The reversal of 129959749 is 947959921.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 129959749 - 2³ = 129959741 is a prime.

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 129959749.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129959741) 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, 915139 + ... + 915280.

It is an arithmetic number, because the mean of its divisors is an integer number (32947560).

Almost surely, 2^129959749 is an apocalyptic number.

It is an amenable number.

129959749 is a deficient number, since it is larger than the sum of its proper divisors (1830491).

129959749 is an equidigital number, since it uses as much as digits as its factorization.

129959749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1830490.

The product of its digits is 1837080, while the sum is 55.

The square root of 129959749 is about 11399.9889912228. The cubic root of 129959749 is about 506.5274135912.

The spelling of 129959749 in words is "one hundred twenty-nine million, nine hundred fifty-nine thousand, seven hundred forty-nine".