1820131 has 4 divisors (see below), whose sum is σ = 1825200. Its totient is φ = 1815064.

The previous prime is 1820129. The next prime is 1820153. The reversal of 1820131 is 1310281.

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

It is a cyclic number.

It is not a de Polignac number, because 1820131 - 2¹ = 1820129 is a prime.

It is a super-2 number, since 2×1820131² = 6625753714322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1820111) 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, 1951 + ... + 2728.

It is an arithmetic number, because the mean of its divisors is an integer number (456300).

2^1820131 is an apocalyptic number.

1820131 is a deficient number, since it is larger than the sum of its proper divisors (5069).

1820131 is an equidigital number, since it uses as much as digits as its factorization.

1820131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5068.

The product of its (nonzero) digits is 48, while the sum is 16.

The square root of 1820131 is about 1349.1223072798. The cubic root of 1820131 is about 122.0958442399.

The spelling of 1820131 in words is "one million, eight hundred twenty thousand, one hundred thirty-one".