805121 has 2 divisors, whose sum is σ = 805122. Its totient is φ = 805120.

The previous prime is 805111. The next prime is 805153. The reversal of 805121 is 121508.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 801025 + 4096 = 895^2 + 64^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-805121 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 805121.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 805121.

It is not a weakly prime, because it can be changed into another prime (805111) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 402560 + 402561.

It is an arithmetic number, because the mean of its divisors is an integer number (402561).

2⁸⁰⁵¹²¹ is an apocalyptic number.

It is an amenable number.

805121 is a deficient number, since it is larger than the sum of its proper divisors (1).

805121 is an equidigital number, since it uses as much as digits as its factorization.

805121 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 80, while the sum is 17.

The square root of 805121 is about 897.2853503763. The cubic root of 805121 is about 93.0294353196.

Adding to 805121 its reverse (121508), we get a palindrome (926629).

It can be divided in two parts, 8051 and 21, that multiplied together give a triangular number (169071 = T₅₈₁).

The spelling of 805121 in words is "eight hundred five thousand, one hundred twenty-one".