3647521 has 4 divisors (see below), whose sum is σ = 3655044. Its totient is φ = 3640000.

The previous prime is 3647489. The next prime is 3647531. The reversal of 3647521 is 1257463.

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 1288225 + 2359296 = 1135^2 + 1536^2 .

It is a cyclic number.

It is not a de Polignac number, because 3647521 - 2⁵ = 3647489 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 3647521.

It is not an unprimeable number, because it can be changed into a prime (3647531) 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, 2980 + ... + 4021.

It is an arithmetic number, because the mean of its divisors is an integer number (913761).

Almost surely, 2^3647521 is an apocalyptic number.

It is an amenable number.

3647521 is a deficient number, since it is larger than the sum of its proper divisors (7523).

3647521 is an equidigital number, since it uses as much as digits as its factorization.

3647521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7522.

The product of its digits is 5040, while the sum is 28.

The square root of 3647521 is about 1909.8484233048. The cubic root of 3647521 is about 153.9333072659.

The spelling of 3647521 in words is "three million, six hundred forty-seven thousand, five hundred twenty-one".