1340921 has 4 divisors (see below), whose sum is σ = 1344144. Its totient is φ = 1337700.

The previous prime is 1340903. The next prime is 1340929. The reversal of 1340921 is 1290431.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1340921 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1340893 and 1340902.

It is not an unprimeable number, because it can be changed into a prime (1340929) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 875 + ... + 1856.

It is an arithmetic number, because the mean of its divisors is an integer number (336036).

2^1340921 is an apocalyptic number.

It is an amenable number.

1340921 is a deficient number, since it is larger than the sum of its proper divisors (3223).

1340921 is an equidigital number, since it uses as much as digits as its factorization.

1340921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3222.

The product of its (nonzero) digits is 216, while the sum is 20.

The square root of 1340921 is about 1157.9814333572. The cubic root of 1340921 is about 110.2726295282.

The spelling of 1340921 in words is "one million, three hundred forty thousand, nine hundred twenty-one".