129120621 has 8 divisors (see below), whose sum is σ = 196755264. Its totient is φ = 73783200.

The previous prime is 129120619. The next prime is 129120623. The reversal of 129120621 is 126021921.

It is an interprime number because it is at equal distance from previous prime (129120619) and next prime (129120623).

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

It is not a de Polignac number, because 129120621 - 2¹ = 129120619 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 129120591 and 129120600.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129120623) 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, 3074280 + ... + 3074321.

It is an arithmetic number, because the mean of its divisors is an integer number (24594408).

Almost surely, 2^129120621 is an apocalyptic number.

It is an amenable number.

129120621 is a deficient number, since it is larger than the sum of its proper divisors (67634643).

129120621 is an equidigital number, since it uses as much as digits as its factorization.

129120621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6148611.

The product of its (nonzero) digits is 432, while the sum is 24.

The square root of 129120621 is about 11363.1254943347. The cubic root of 129120621 is about 505.4348716284.

It can be divided in two parts, 1291 and 20621, that added together give a palindrome (21912).

The spelling of 129120621 in words is "one hundred twenty-nine million, one hundred twenty thousand, six hundred twenty-one".