3721605 has 16 divisors (see below), whose sum is σ = 6001344. Its totient is φ = 1969280.

The previous prime is 3721603. The next prime is 3721621. The reversal of 3721605 is 5061273.

It is not a de Polignac number, because 3721605 - 2¹ = 3721603 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3721603) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1150 + ... + 2960.

It is an arithmetic number, because the mean of its divisors is an integer number (375084).

Almost surely, 2^3721605 is an apocalyptic number.

It is an amenable number.

3721605 is a deficient number, since it is larger than the sum of its proper divisors (2279739).

3721605 is a wasteful number, since it uses less digits than its factorization.

3721605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1956.

The product of its (nonzero) digits is 1260, while the sum is 24.

The square root of 3721605 is about 1929.1461841965. The cubic root of 3721605 is about 154.9684986277.

Adding to 3721605 its reverse (5061273), we get a palindrome (8782878).

The spelling of 3721605 in words is "three million, seven hundred twenty-one thousand, six hundred five".