220820129 has 4 divisors (see below), whose sum is σ = 221388180. Its totient is φ = 220252080.

The previous prime is 220820111. The next prime is 220820143. The reversal of 220820129 is 921028022.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 52417600 + 168402529 = 7240^2 + 12977^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-220820129 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 220820098 and 220820107.

It is not an unprimeable number, because it can be changed into a prime (220823129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 283442 + ... + 284219.

It is an arithmetic number, because the mean of its divisors is an integer number (55347045).

Almost surely, 2^220820129 is an apocalyptic number.

It is an amenable number.

220820129 is a deficient number, since it is larger than the sum of its proper divisors (568051).

220820129 is an equidigital number, since it uses as much as digits as its factorization.

220820129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 568050.

The product of its (nonzero) digits is 1152, while the sum is 26.

The square root of 220820129 is about 14860.0177994510. The cubic root of 220820129 is about 604.4302894521.

The spelling of 220820129 in words is "two hundred twenty million, eight hundred twenty thousand, one hundred twenty-nine".