1646669 has 2 divisors, whose sum is σ = 1646670. Its totient is φ = 1646668.

The previous prime is 1646647. The next prime is 1646677. The reversal of 1646669 is 9666461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1357225 + 289444 = 1165^2 + 538^2 .

It is a cyclic number.

It is not a de Polignac number, because 1646669 - 2⁸ = 1646413 is a prime.

It is a super-2 number, since 2×1646669² = 5423037591122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1646609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 823334 + 823335.

It is an arithmetic number, because the mean of its divisors is an integer number (823335).

2^1646669 is an apocalyptic number.

It is an amenable number.

1646669 is a deficient number, since it is larger than the sum of its proper divisors (1).

1646669 is an equidigital number, since it uses as much as digits as its factorization.

1646669 is an evil number, because the sum of its binary digits is even.

The product of its digits is 46656, while the sum is 38.

The square root of 1646669 is about 1283.2260128286. The cubic root of 1646669 is about 118.0870037270.

The spelling of 1646669 in words is "one million, six hundred forty-six thousand, six hundred sixty-nine".