129480821 has 4 divisors (see below), whose sum is σ = 129509472. Its totient is φ = 129452172.

The previous prime is 129480803. The next prime is 129480847. The reversal of 129480821 is 128084921.

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, and also an emirpimes, since its reverse is a distinct semiprime: 128084921 = 313 ⋅409217.

It is a cyclic number.

It is not a de Polignac number, because 129480821 - 2¹⁴ = 129464437 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (129486821) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5891 + ... + 17136.

It is an arithmetic number, because the mean of its divisors is an integer number (32377368).

Almost surely, 2^129480821 is an apocalyptic number.

It is an amenable number.

129480821 is a deficient number, since it is larger than the sum of its proper divisors (28651).

129480821 is an equidigital number, since it uses as much as digits as its factorization.

129480821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28650.

The product of its (nonzero) digits is 9216, while the sum is 35.

The square root of 129480821 is about 11378.9639686573. The cubic root of 129480821 is about 505.9044289810.

The spelling of 129480821 in words is "one hundred twenty-nine million, four hundred eighty thousand, eight hundred twenty-one".