1646321 has 2 divisors, whose sum is σ = 1646322. Its totient is φ = 1646320.

The previous prime is 1646311. The next prime is 1646347. The reversal of 1646321 is 1236461.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1638400 + 7921 = 1280^2 + 89^2 .

It is a cyclic number.

It is not a de Polignac number, because 1646321 - 2¹⁴ = 1629937 is a prime.

It is equal to p₁₂₄₃₈₅ and since 1646321 and 124385 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (1646311) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 823160 + 823161.

It is an arithmetic number, because the mean of its divisors is an integer number (823161).

2^1646321 is an apocalyptic number.

It is an amenable number.

1646321 is a deficient number, since it is larger than the sum of its proper divisors (1).

1646321 is an equidigital number, since it uses as much as digits as its factorization.

1646321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 864, while the sum is 23.

The square root of 1646321 is about 1283.0904099088. The cubic root of 1646321 is about 118.0786844731.

The spelling of 1646321 in words is "one million, six hundred forty-six thousand, three hundred twenty-one".