3638581 has 4 divisors (see below), whose sum is σ = 3654700. Its totient is φ = 3622464.

The previous prime is 3638573. The next prime is 3638639. The reversal of 3638581 is 1858363.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 2220100 + 1418481 = 1490^2 + 1191^2 .

It is a cyclic number.

It is not a de Polignac number, because 3638581 - 2³ = 3638573 is a prime.

It is a super-2 number, since 2×3638581² = 26478543387122, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3638521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7716 + ... + 8173.

It is an arithmetic number, because the mean of its divisors is an integer number (913675).

Almost surely, 2^3638581 is an apocalyptic number.

It is an amenable number.

3638581 is a deficient number, since it is larger than the sum of its proper divisors (16119).

3638581 is a wasteful number, since it uses less digits than its factorization.

3638581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16118.

The product of its digits is 17280, while the sum is 34.

The square root of 3638581 is about 1907.5064875381. The cubic root of 3638581 is about 153.8074419073.

The spelling of 3638581 in words is "three million, six hundred thirty-eight thousand, five hundred eighty-one".