129761949 has 4 divisors (see below), whose sum is σ = 173015936. Its totient is φ = 86507964.

The previous prime is 129761941. The next prime is 129761981. The reversal of 129761949 is 949167921.

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 not a de Polignac number, because 129761949 - 2³ = 129761941 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 129761898 and 129761907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129761941) 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, 21626989 + ... + 21626994.

It is an arithmetic number, because the mean of its divisors is an integer number (43253984).

Almost surely, 2^129761949 is an apocalyptic number.

It is an amenable number.

129761949 is a deficient number, since it is larger than the sum of its proper divisors (43253987).

129761949 is an equidigital number, since it uses as much as digits as its factorization.

129761949 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43253986.

The product of its digits is 244944, while the sum is 48.

The square root of 129761949 is about 11391.3102407054. The cubic root of 129761949 is about 506.2703032247.

The spelling of 129761949 in words is "one hundred twenty-nine million, seven hundred sixty-one thousand, nine hundred forty-nine".