291091967985 has 64 divisors (see below), whose sum is σ = 575731054080. Its totient is φ = 122297886720.

The previous prime is 291091967939. The next prime is 291091967987. The reversal of 291091967985 is 589769190192.

It is not a de Polignac number, because 291091967985 - 2⁸ = 291091967729 is a prime.

It is not an unprimeable number, because it can be changed into a prime (291091967987) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 153036 + ... + 778205.

It is an arithmetic number, because the mean of its divisors is an integer number (8995797720).

Almost surely, 2^291091967985 is an apocalyptic number.

It is an amenable number.

291091967985 is a deficient number, since it is larger than the sum of its proper divisors (284639086095).

291091967985 is a wasteful number, since it uses less digits than its factorization.

291091967985 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 931498.

The product of its (nonzero) digits is 22044960, while the sum is 66.

The spelling of 291091967985 in words is "two hundred ninety-one billion, ninety-one million, nine hundred sixty-seven thousand, nine hundred eighty-five".