861121 has 2 divisors, whose sum is σ = 861122. Its totient is φ = 861120.

The previous prime is 861109. The next prime is 861131. The reversal of 861121 is 121168.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 748225 + 112896 = 865^2 + 336^2 .

It is a cyclic number.

It is not a de Polignac number, because 861121 - 2⁵ = 861089 is a prime.

It is not a weakly prime, because it can be changed into another prime (861131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 430560 + 430561.

It is an arithmetic number, because the mean of its divisors is an integer number (430561).

2⁸⁶¹¹²¹ is an apocalyptic number.

It is an amenable number.

861121 is a deficient number, since it is larger than the sum of its proper divisors (1).

861121 is an equidigital number, since it uses as much as digits as its factorization.

861121 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96, while the sum is 19.

The square root of 861121 is about 927.9660554137. The cubic root of 861121 is about 95.1381554051.

Adding to 861121 its reverse (121168), we get a palindrome (982289).

The spelling of 861121 in words is "eight hundred sixty-one thousand, one hundred twenty-one".