291145 has 4 divisors (see below), whose sum is σ = 349380. Its totient is φ = 232912.

The previous prime is 291143. The next prime is 291167. The reversal of 291145 is 541192.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 149769 + 141376 = 387^2 + 376^2 .

It is a cyclic number.

It is not a de Polignac number, because 291145 - 2¹ = 291143 is a prime.

It is a super-2 number, since 2×291145² = 169530822050, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (291143) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 29110 + ... + 29119.

It is an arithmetic number, because the mean of its divisors is an integer number (87345).

2²⁹¹¹⁴⁵ is an apocalyptic number.

It is an amenable number.

291145 is a deficient number, since it is larger than the sum of its proper divisors (58235).

291145 is an equidigital number, since it uses as much as digits as its factorization.

291145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58234.

The product of its digits is 360, while the sum is 22.

The square root of 291145 is about 539.5785392322. The cubic root of 291145 is about 66.2780586025.

Subtracting 291145 from its reverse (541192), we obtain a cube (250047 = 63³).

It can be divided in two parts, 291 and 145, that multiplied together give a triangular number (42195 = T₂₉₀).

The spelling of 291145 in words is "two hundred ninety-one thousand, one hundred forty-five".