291740561 has 6 divisors (see below), whose sum is σ = 339371730. Its totient is φ = 250063296.

The previous prime is 291740557. The next prime is 291740569. The reversal of 291740561 is 165047192.

It can be written as a sum of positive squares in only one way, i.e., 291726400 + 14161 = 17080^2 + 119^2 .

It is not a de Polignac number, because 291740561 - 2² = 291740557 is a prime.

It is a super-2 number, since 2×291740561² = 170225109865189442, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (291740569) 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, 2976896 + ... + 2976993.

It is an arithmetic number, because the mean of its divisors is an integer number (56561955).

Almost surely, 2^291740561 is an apocalyptic number.

It is an amenable number.

291740561 is a deficient number, since it is larger than the sum of its proper divisors (47631169).

291740561 is an equidigital number, since it uses as much as digits as its factorization.

291740561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5953903 (or 5953896 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 291740561 is about 17080.4145441497. The cubic root of 291740561 is about 663.2322022593.

The spelling of 291740561 in words is "two hundred ninety-one million, seven hundred forty thousand, five hundred sixty-one".