291488761 has 2 divisors, whose sum is σ = 291488762. Its totient is φ = 291488760.

The previous prime is 291488759. The next prime is 291488797. The reversal of 291488761 is 167884192.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 210830400 + 80658361 = 14520^2 + 8981^2 .

It is a cyclic number.

It is not a de Polignac number, because 291488761 - 2¹ = 291488759 is a prime.

Together with 291488759, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (291488731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 145744380 + 145744381.

It is an arithmetic number, because the mean of its divisors is an integer number (145744381).

Almost surely, 2^291488761 is an apocalyptic number.

It is an amenable number.

291488761 is a deficient number, since it is larger than the sum of its proper divisors (1).

291488761 is an equidigital number, since it uses as much as digits as its factorization.

291488761 is an evil number, because the sum of its binary digits is even.

The product of its digits is 193536, while the sum is 46.

The square root of 291488761 is about 17073.0419375107. The cubic root of 291488761 is about 663.0413364010.

The spelling of 291488761 in words is "two hundred ninety-one million, four hundred eighty-eight thousand, seven hundred sixty-one".