1312821 has 8 divisors (see below), whose sum is σ = 1944960. Its totient is φ = 875196.

The previous prime is 1312813. The next prime is 1312823. The reversal of 1312821 is 1282131.

It is not a de Polignac number, because 1312821 - 2³ = 1312813 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1312794 and 1312803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1312823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 24285 + ... + 24338.

It is an arithmetic number, because the mean of its divisors is an integer number (243120).

2^1312821 is an apocalyptic number.

It is an amenable number.

1312821 is a deficient number, since it is larger than the sum of its proper divisors (632139).

1312821 is an equidigital number, since it uses as much as digits as its factorization.

1312821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48632 (or 48626 counting only the distinct ones).

The product of its digits is 96, while the sum is 18.

The square root of 1312821 is about 1145.7840110597. The cubic root of 1312821 is about 109.4969036467.

Adding to 1312821 its reverse (1282131), we get a palindrome (2594952).

The spelling of 1312821 in words is "one million, three hundred twelve thousand, eight hundred twenty-one".