291601 has 6 divisors (see below), whose sum is σ = 310070. Its totient is φ = 274176.

The previous prime is 291569. The next prime is 291619. The reversal of 291601 is 106192.

It is a Cunningham number, because it is equal to 540²+1.

It can be written as a sum of positive squares in 3 ways, for example, as 90000 + 201601 = 300^2 + 449^2 .

It is not a de Polignac number, because 291601 - 2⁵ = 291569 is a prime.

It is a super-2 number, since 2×291601² = 170062286402, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (291661) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 216 + ... + 793.

291601 is a Friedman number, since it can be written as (10*9*6)^2+1, using all its digits and the basic arithmetic operations.

2²⁹¹⁶⁰¹ is an apocalyptic number.

291601 is the 289-th nonagonal number.

It is an amenable number.

291601 is a deficient number, since it is larger than the sum of its proper divisors (18469).

291601 is a wasteful number, since it uses less digits than its factorization.

291601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1043 (or 1026 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 291601 is about 540.0009259251. Note that the first 3 decimals coincide. The cubic root of 291601 is about 66.3126427786.

Adding to 291601 its reverse (106192), we get a palindrome (397793).

It can be divided in two parts, 29160 and 1, that added together give a triangular number (29161 = T₂₄₁).

The spelling of 291601 in words is "two hundred ninety-one thousand, six hundred one".