1820129 has 2 divisors, whose sum is σ = 1820130. Its totient is φ = 1820128.

The previous prime is 1820123. The next prime is 1820153. The reversal of 1820129 is 9210281.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1817104 + 3025 = 1348^2 + 55^2 .

It is a cyclic number.

It is not a de Polignac number, because 1820129 - 2²⁰ = 771553 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1820123) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 910064 + 910065.

It is an arithmetic number, because the mean of its divisors is an integer number (910065).

2^1820129 is an apocalyptic number.

It is an amenable number.

1820129 is a deficient number, since it is larger than the sum of its proper divisors (1).

1820129 is an equidigital number, since it uses as much as digits as its factorization.

1820129 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 1820129 is about 1349.1215660570. The cubic root of 1820129 is about 122.0957995194.

The spelling of 1820129 in words is "one million, eight hundred twenty thousand, one hundred twenty-nine".