1296821 has 4 divisors (see below), whose sum is σ = 1302444. Its totient is φ = 1291200.

The previous prime is 1296817. The next prime is 1296829. The reversal of 1296821 is 1286921.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1286921 = 499 ⋅2579.

It can be written as a sum of positive squares in 2 ways, for example, as 703921 + 592900 = 839^2 + 770^2 .

It is a cyclic number.

It is not a de Polignac number, because 1296821 - 2² = 1296817 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1296829) 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, 2450 + ... + 2931.

It is an arithmetic number, because the mean of its divisors is an integer number (325611).

2^1296821 is an apocalyptic number.

It is an amenable number.

1296821 is a deficient number, since it is larger than the sum of its proper divisors (5623).

1296821 is an equidigital number, since it uses as much as digits as its factorization.

1296821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5622.

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

The square root of 1296821 is about 1138.7804880661. The cubic root of 1296821 is about 109.0502531794.

The spelling of 1296821 in words is "one million, two hundred ninety-six thousand, eight hundred twenty-one".