287891291281 has 16 divisors (see below), whose sum is σ = 320773294080. Its totient is φ = 256128601680.

The previous prime is 287891291279. The next prime is 287891291299. The reversal of 287891291281 is 182192198782.

It is a cyclic number.

It is not a de Polignac number, because 287891291281 - 2¹ = 287891291279 is a prime.

It is a super-2 number, since 2×287891291281² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (287891291081) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9735340 + ... + 9764866.

It is an arithmetic number, because the mean of its divisors is an integer number (20048330880).

Almost surely, 2^287891291281 is an apocalyptic number.

It is an amenable number.

287891291281 is a deficient number, since it is larger than the sum of its proper divisors (32882002799).

287891291281 is a wasteful number, since it uses less digits than its factorization.

287891291281 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48444.

The product of its digits is 2322432, while the sum is 58.

The spelling of 287891291281 in words is "two hundred eighty-seven billion, eight hundred ninety-one million, two hundred ninety-one thousand, two hundred eighty-one".