291391597249 has 9 divisors (see below), whose sum is σ = 295169986083. Its totient is φ = 287660991072.

The previous prime is 291391597241. The next prime is 291391597267. The reversal of 291391597249 is 942795193192.

The square root of 291391597249 is 539807.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 36398916225 + 254992681024 = 190785^2 + 504968^2 .

It is not a de Polignac number, because 291391597249 - 2³ = 291391597241 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (291391597241) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 42641337 + ... + 42648169.

Almost surely, 2^291391597249 is an apocalyptic number.

291391597249 is the 539807-th square number.

291391597249 is the 269904-th centered octagonal number.

It is an amenable number.

291391597249 is a deficient number, since it is larger than the sum of its proper divisors (3778388834).

291391597249 is an frugal number, since it uses more digits than its factorization.

291391597249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13824 (or 6912 counting only the distinct ones).

The product of its digits is 11022480, while the sum is 61.

The spelling of 291391597249 in words is "two hundred ninety-one billion, three hundred ninety-one million, five hundred ninety-seven thousand, two hundred forty-nine".