810121 has 8 divisors (see below), whose sum is σ = 882504. Its totient is φ = 739200.

The previous prime is 810109. The next prime is 810137. The reversal of 810121 is 121018.

It can be written as a sum of positive squares in 4 ways, for example, as 26896 + 783225 = 164^2 + 885^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 810121 - 2⁷ = 809993 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (810151) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1005 + ... + 1621.

It is an arithmetic number, because the mean of its divisors is an integer number (110313).

2⁸¹⁰¹²¹ is an apocalyptic number.

It is an amenable number.

810121 is a deficient number, since it is larger than the sum of its proper divisors (72383).

810121 is a wasteful number, since it uses less digits than its factorization.

810121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 731.

The product of its (nonzero) digits is 16, while the sum is 13.

The square root of 810121 is about 900.0672197120. The cubic root of 810121 is about 93.2216166158.

Adding to 810121 its reverse (121018), we get a palindrome (931139).

The spelling of 810121 in words is "eight hundred ten thousand, one hundred twenty-one".