820131 has 16 divisors (see below), whose sum is σ = 1247904. Its totient is φ = 474624.

The previous prime is 820129. The next prime is 820133. The reversal of 820131 is 131028.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (820129) and next prime (820133).

It is not a de Polignac number, because 820131 - 2¹ = 820129 is a prime.

It is a super-2 number, since 2×820131² = 1345229714322, which contains 22 as substring.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 820131.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (820133) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 45 + ... + 1281.

It is an arithmetic number, because the mean of its divisors is an integer number (77994).

2⁸²⁰¹³¹ is an apocalyptic number.

820131 is a deficient number, since it is larger than the sum of its proper divisors (427773).

820131 is a wasteful number, since it uses less digits than its factorization.

820131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1270.

The product of its (nonzero) digits is 48, while the sum is 15.

The square root of 820131 is about 905.6108435747. The cubic root of 820131 is about 93.6040003039.

Adding to 820131 its reverse (131028), we get a palindrome (951159).

The spelling of 820131 in words is "eight hundred twenty thousand, one hundred thirty-one".