129735221 has 8 divisors (see below), whose sum is σ = 161747904. Its totient is φ = 101092320.

The previous prime is 129735191. The next prime is 129735239. The reversal of 129735221 is 122537921.

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

It is not a de Polignac number, because 129735221 - 2¹⁴ = 129718837 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 (129735421) 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 7 ways as a sum of consecutive naturals, for example, 842360 + ... + 842513.

It is an arithmetic number, because the mean of its divisors is an integer number (20218488).

Almost surely, 2^129735221 is an apocalyptic number.

129735221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

129735221 is a deficient number, since it is larger than the sum of its proper divisors (32012683).

129735221 is a wasteful number, since it uses less digits than its factorization.

129735221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1684891.

The product of its digits is 7560, while the sum is 32.

The square root of 129735221 is about 11390.1370053218. The cubic root of 129735221 is about 506.2355407952.

The spelling of 129735221 in words is "one hundred twenty-nine million, seven hundred thirty-five thousand, two hundred twenty-one".