287138691 has 12 divisors (see below), whose sum is σ = 474006832. Its totient is φ = 164079216.

The previous prime is 287138689. The next prime is 287138737. The reversal of 287138691 is 196831782.

It is not a de Polignac number, because 287138691 - 2¹ = 287138689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (287138791) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2278816 + ... + 2278941.

Almost surely, 2^287138691 is an apocalyptic number.

287138691 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

287138691 is a deficient number, since it is larger than the sum of its proper divisors (186868141).

287138691 is a wasteful number, since it uses less digits than its factorization.

287138691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4557770 (or 4557767 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 287138691 is about 16945.1671871363. The cubic root of 287138691 is about 659.7264637839.

The spelling of 287138691 in words is "two hundred eighty-seven million, one hundred thirty-eight thousand, six hundred ninety-one".