291278985 has 16 divisors (see below), whose sum is σ = 478643136. Its totient is φ = 151149888.

The previous prime is 291278983. The next prime is 291278989. The reversal of 291278985 is 589872192.

It is not a de Polignac number, because 291278985 - 2¹ = 291278983 is a prime.

It is not an unprimeable number, because it can be changed into a prime (291278983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 261859 + ... + 262968.

It is an arithmetic number, because the mean of its divisors is an integer number (29915196).

Almost surely, 2^291278985 is an apocalyptic number.

It is an amenable number.

291278985 is a deficient number, since it is larger than the sum of its proper divisors (187364151).

291278985 is a wasteful number, since it uses less digits than its factorization.

291278985 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 524872.

The product of its digits is 725760, while the sum is 51.

The square root of 291278985 is about 17066.8973454462. The cubic root of 291278985 is about 662.8822410284.

The spelling of 291278985 in words is "two hundred ninety-one million, two hundred seventy-eight thousand, nine hundred eighty-five".