286981 has 2 divisors, whose sum is σ = 286982. Its totient is φ = 286980.

The previous prime is 286973. The next prime is 286987. The reversal of 286981 is 189682.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 216225 + 70756 = 465^2 + 266^2 .

It is a cyclic number.

It is not a de Polignac number, because 286981 - 2³ = 286973 is a prime.

It is a super-2 number, since 2×286981² = 164716188722, which contains 22 as substring.

It is an Ulam number.

286981 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (286987) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 143490 + 143491.

It is an arithmetic number, because the mean of its divisors is an integer number (143491).

2²⁸⁶⁹⁸¹ is an apocalyptic number.

It is an amenable number.

286981 is a deficient number, since it is larger than the sum of its proper divisors (1).

286981 is an equidigital number, since it uses as much as digits as its factorization.

286981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 34.

The square root of 286981 is about 535.7060761276. The cubic root of 286981 is about 65.9605672010.

The spelling of 286981 in words is "two hundred eighty-six thousand, nine hundred eighty-one".