129561383726 has 4 divisors (see below), whose sum is σ = 194342075592. Its totient is φ = 64780691862.

The previous prime is 129561383713. The next prime is 129561383729. The reversal of 129561383726 is 627383165921.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129561383729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32390345930 + ... + 32390345933.

It is an arithmetic number, because the mean of its divisors is an integer number (48585518898).

Almost surely, 2^129561383726 is an apocalyptic number.

129561383726 is a deficient number, since it is larger than the sum of its proper divisors (64780691866).

129561383726 is an equidigital number, since it uses as much as digits as its factorization.

129561383726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64780691865.

The product of its digits is 3265920, while the sum is 53.

The spelling of 129561383726 in words is "one hundred twenty-nine billion, five hundred sixty-one million, three hundred eighty-three thousand, seven hundred twenty-six".