129680621 has 4 divisors (see below), whose sum is σ = 148206432. Its totient is φ = 111154812.

The previous prime is 129680591. The next prime is 129680623. The reversal of 129680621 is 126086921.

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 129680621 - 2¹⁸ = 129418477 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129680623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9262895 + ... + 9262908.

It is an arithmetic number, because the mean of its divisors is an integer number (37051608).

Almost surely, 2^129680621 is an apocalyptic number.

It is an amenable number.

129680621 is a deficient number, since it is larger than the sum of its proper divisors (18525811).

129680621 is an equidigital number, since it uses as much as digits as its factorization.

129680621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18525810.

The product of its (nonzero) digits is 10368, while the sum is 35.

The square root of 129680621 is about 11387.7399425874. The cubic root of 129680621 is about 506.1645132084.

The spelling of 129680621 in words is "one hundred twenty-nine million, six hundred eighty thousand, six hundred twenty-one".