1646609 has 2 divisors, whose sum is σ = 1646610. Its totient is φ = 1646608.

The previous prime is 1646581. The next prime is 1646629. The reversal of 1646609 is 9066461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1050625 + 595984 = 1025^2 + 772^2 .

It is a cyclic number.

It is not a de Polignac number, because 1646609 - 2¹² = 1642513 is a prime.

It is a super-2 number, since 2×1646609² = 5422642397762, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (1646629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 823304 + 823305.

It is an arithmetic number, because the mean of its divisors is an integer number (823305).

2^1646609 is an apocalyptic number.

It is an amenable number.

1646609 is a deficient number, since it is larger than the sum of its proper divisors (1).

1646609 is an equidigital number, since it uses as much as digits as its factorization.

1646609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7776, while the sum is 32.

The square root of 1646609 is about 1283.2026340372. The cubic root of 1646609 is about 118.0855694565.

The spelling of 1646609 in words is "one million, six hundred forty-six thousand, six hundred nine".