3638664 has 48 divisors (see below), whose sum is σ = 9975420. Its totient is φ = 1198080.

The previous prime is 3638653. The next prime is 3638699. The reversal of 3638664 is 4668363.

It can be written as a sum of positive squares in 2 ways, for example, as 3572100 + 66564 = 1890^2 + 258^2 .

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 6724 + ... + 7244.

Almost surely, 2^3638664 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 3638664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4987710).

3638664 is an abundant number, since it is smaller than the sum of its proper divisors (6336756).

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

3638664 is a wasteful number, since it uses less digits than its factorization.

3638664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 630 (or 623 counting only the distinct ones).

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

The square root of 3638664 is about 1907.5282435655. The cubic root of 3638664 is about 153.8086114035.

The spelling of 3638664 in words is "three million, six hundred thirty-eight thousand, six hundred sixty-four".