842581 has 2 divisors, whose sum is σ = 842582. Its totient is φ = 842580.

The previous prime is 842551. The next prime is 842587. The reversal of 842581 is 185248.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 731025 + 111556 = 855^2 + 334^2 .

It is a cyclic number.

It is not a de Polignac number, because 842581 - 2¹⁷ = 711509 is a prime.

It is a super-2 number, since 2×842581² = 1419885483122, which contains 22 as substring.

It is a plaindrome in base 13.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (842587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 421290 + 421291.

It is an arithmetic number, because the mean of its divisors is an integer number (421291).

2⁸⁴²⁵⁸¹ is an apocalyptic number.

It is an amenable number.

842581 is a deficient number, since it is larger than the sum of its proper divisors (1).

842581 is an equidigital number, since it uses as much as digits as its factorization.

842581 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2560, while the sum is 28.

The square root of 842581 is about 917.9221099854. The cubic root of 842581 is about 94.4504186404.

The spelling of 842581 in words is "eight hundred forty-two thousand, five hundred eighty-one".