1312021 has 4 divisors (see below), whose sum is σ = 1321600.
Its totient is φ = 1302444.
The previous prime is 1312019. The next prime is 1312027. The reversal of 1312021 is 1202131.
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: 1202131 = 7 ⋅171733.
It is a cyclic number.
It is not a de Polignac number, because 1312021 - 21 = 1312019 is a prime.
It is a Duffinian number.
1312021 is a lucky number.
It is a nialpdrome in base 12.
It is a junction number, because it is equal to n+sod(n) for n = 1311989 and 1312007.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (1312027) 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 3 ways as a sum of consecutive naturals, for example, 4581 + ... + 4858.
It is an arithmetic number, because the mean of its divisors is an integer number (330400).
21312021 is an apocalyptic number.
It is an amenable number.
1312021 is a deficient number, since it is larger than the sum of its proper divisors (9579).
1312021 is an equidigital number, since it uses as much as digits as its factorization.
1312021 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 9578.
The product of its (nonzero) digits is 12, while the sum is 10.
The square root of 1312021 is about 1145.4348519231.
The cubic root of 1312021 is about 109.4746575771.
Adding to 1312021 its reverse (1202131), we get a palindrome (2514152).
The spelling of 1312021 in words is "one million, three hundred twelve thousand, twenty-one".