1286921 has 4 divisors (see below), whose sum is σ = 1290000. Its totient is φ = 1283844.

The previous prime is 1286881. The next prime is 1286939. The reversal of 1286921 is 1296821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1296821 = 241 ⋅5381.

It is a cyclic number.

It is not a de Polignac number, because 1286921 - 2¹⁴ = 1270537 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1286941) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 791 + ... + 1788.

It is an arithmetic number, because the mean of its divisors is an integer number (322500).

2^1286921 is an apocalyptic number.

It is an amenable number.

1286921 is a deficient number, since it is larger than the sum of its proper divisors (3079).

1286921 is an equidigital number, since it uses as much as digits as its factorization.

1286921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3078.

The product of its digits is 1728, while the sum is 29.

The square root of 1286921 is about 1134.4254052162. The cubic root of 1286921 is about 108.7720455593.

The spelling of 1286921 in words is "one million, two hundred eighty-six thousand, nine hundred twenty-one".