3643866 has 40 divisors (see below), whose sum is σ = 8293824. Its totient is φ = 1195560.

The previous prime is 3643859. The next prime is 3643873. The reversal of 3643866 is 6683463.

3643866 is a `hidden beast` number, since 3 + 643 + 8 + 6 + 6 = 666.

It is an interprime number because it is at equal distance from previous prime (3643859) and next prime (3643873).

It is an Ulam number.

It is a d-powerful number, because it can be written as 3² + 6⁷ + 4⁶ + 3⁴ + 8³ + 6⁸ + 6⁸ .

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 3643866.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 13311 + ... + 13581.

Almost surely, 2^3643866 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3643866, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4146912).

3643866 is an abundant number, since it is smaller than the sum of its proper divisors (4649958).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3643866 is a wasteful number, since it uses less digits than its factorization.

3643866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 368 (or 359 counting only the distinct ones).

The product of its digits is 62208, while the sum is 36.

The square root of 3643866 is about 1908.8913012532. The cubic root of 3643866 is about 153.8818737700.

The spelling of 3643866 in words is "three million, six hundred forty-three thousand, eight hundred sixty-six".