3649644 has 48 divisors (see below), whose sum is σ = 9676800. Its totient is φ = 1189008.

The previous prime is 3649637. The next prime is 3649669. The reversal of 3649644 is 4469463.

3649644 is a `hidden beast` number, since 3 + 6 + 4 + 9 + 644 = 666.

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 a junction number, because it is equal to n+sod(n) for n = 3649599 and 3649608.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4717 + ... + 5435.

It is an arithmetic number, because the mean of its divisors is an integer number (201600).

Almost surely, 2^3649644 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 3649644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (4838400).

3649644 is an abundant number, since it is smaller than the sum of its proper divisors (6027156).

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

3649644 is a wasteful number, since it uses less digits than its factorization.

3649644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 779 (or 771 counting only the distinct ones).

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

The square root of 3649644 is about 1910.4041457241. The cubic root of 3649644 is about 153.9631665437.

The spelling of 3649644 in words is "three million, six hundred forty-nine thousand, six hundred forty-four".