1286981 has 2 divisors, whose sum is σ = 1286982. Its totient is φ = 1286980.

The previous prime is 1286969. The next prime is 1286983. The reversal of 1286981 is 1896821.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 748225 + 538756 = 865^2 + 734^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1286981 is a prime.

It is a super-2 number, since 2×1286981² = 3312640188722, which contains 22 as substring.

Together with 1286983, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1286983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 643490 + 643491.

It is an arithmetic number, because the mean of its divisors is an integer number (643491).

2^1286981 is an apocalyptic number.

It is an amenable number.

1286981 is a deficient number, since it is larger than the sum of its proper divisors (1).

1286981 is an equidigital number, since it uses as much as digits as its factorization.

1286981 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6912, while the sum is 35.

The square root of 1286981 is about 1134.4518500139. The cubic root of 1286981 is about 108.7737359561.

The spelling of 1286981 in words is "one million, two hundred eighty-six thousand, nine hundred eighty-one".