129751021 has 8 divisors (see below), whose sum is σ = 137579904. Its totient is φ = 121944000.

The previous prime is 129751001. The next prime is 129751031. The reversal of 129751021 is 120157921.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-129751021 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 (129751001) 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, 7686 + ... + 17848.

It is an arithmetic number, because the mean of its divisors is an integer number (17197488).

Almost surely, 2^129751021 is an apocalyptic number.

It is an amenable number.

129751021 is a deficient number, since it is larger than the sum of its proper divisors (7828883).

129751021 is a wasteful number, since it uses less digits than its factorization.

129751021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10931.

The product of its (nonzero) digits is 1260, while the sum is 28.

The square root of 129751021 is about 11390.8305667322. The cubic root of 129751021 is about 506.2560908478.

The spelling of 129751021 in words is "one hundred twenty-nine million, seven hundred fifty-one thousand, twenty-one".