129621005 has 8 divisors (see below), whose sum is σ = 164695032. Its totient is φ = 97596928.

The previous prime is 129621001. The next prime is 129621047. The reversal of 129621005 is 500126921.

It can be written as a sum of positive squares in 4 ways, for example, as 14638276 + 114982729 = 3826^2 + 10723^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 129621005 - 2² = 129621001 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 (129621001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 762392 + ... + 762561.

It is an arithmetic number, because the mean of its divisors is an integer number (20586879).

Almost surely, 2^129621005 is an apocalyptic number.

It is an amenable number.

129621005 is a deficient number, since it is larger than the sum of its proper divisors (35074027).

129621005 is a wasteful number, since it uses less digits than its factorization.

129621005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1524975.

The product of its (nonzero) digits is 1080, while the sum is 26.

The square root of 129621005 is about 11385.1220898153. The cubic root of 129621005 is about 506.0869376781.

Adding to 129621005 its reverse (500126921), we get a palindrome (629747926).

The spelling of 129621005 in words is "one hundred twenty-nine million, six hundred twenty-one thousand, five".