3646781 has 2 divisors, whose sum is σ = 3646782. Its totient is φ = 3646780.

The previous prime is 3646759. The next prime is 3646793. The reversal of 3646781 is 1876463.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3644281 + 2500 = 1909^2 + 50^2 .

It is a cyclic number.

It is not a de Polignac number, because 3646781 - 2⁶ = 3646717 is a prime.

It is a super-2 number, since 2×3646781² = 26598023323922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3646711) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1823390 + 1823391.

It is an arithmetic number, because the mean of its divisors is an integer number (1823391).

Almost surely, 2^3646781 is an apocalyptic number.

It is an amenable number.

3646781 is a deficient number, since it is larger than the sum of its proper divisors (1).

3646781 is an equidigital number, since it uses as much as digits as its factorization.

3646781 is an evil number, because the sum of its binary digits is even.

The product of its digits is 24192, while the sum is 35.

The square root of 3646781 is about 1909.6546808258. The cubic root of 3646781 is about 153.9228966929.

The spelling of 3646781 in words is "three million, six hundred forty-six thousand, seven hundred eighty-one".