291061 has 4 divisors (see below), whose sum is σ = 306400. Its totient is φ = 275724.

The previous prime is 291043. The next prime is 291077. The reversal of 291061 is 160192.

291061 = T₄₃₉ + T₄₄₀ + T₄₄₁.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 291061 - 2¹³ = 282869 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19), and also a Moran number because the ratio is a prime number: 15319 = 291061 / (2 + 9 + 1 + 0 + 6 + 1).

It is the 540-th Hogben number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (291041) by changing a digit.

It is a nontrivial repunit in base 539.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7641 + ... + 7678.

It is an arithmetic number, because the mean of its divisors is an integer number (76600).

2²⁹¹⁰⁶¹ is an apocalyptic number.

291061 is the 441-st centered triangular number.

It is an amenable number.

291061 is a deficient number, since it is larger than the sum of its proper divisors (15339).

291061 is a wasteful number, since it uses less digits than its factorization.

291061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15338.

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

The square root of 291061 is about 539.5006950876. The cubic root of 291061 is about 66.2716838952.

The spelling of 291061 in words is "two hundred ninety-one thousand, sixty-one".