3721645 has 8 divisors (see below), whose sum is σ = 4586904. Its totient is φ = 2896704.

The previous prime is 3721631. The next prime is 3721673. The reversal of 3721645 is 5461273.

It can be written as a sum of positive squares in 4 ways, for example, as 546121 + 3175524 = 739^2 + 1782^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 3721645 - 2¹³ = 3713453 is a prime.

It is a super-3 number, since 3×3721645³ (a number of 21 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9874 + ... + 10243.

It is an arithmetic number, because the mean of its divisors is an integer number (573363).

Almost surely, 2^3721645 is an apocalyptic number.

It is an amenable number.

3721645 is a deficient number, since it is larger than the sum of its proper divisors (865259).

3721645 is a wasteful number, since it uses less digits than its factorization.

3721645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20159.

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

The square root of 3721645 is about 1929.1565514494. The cubic root of 3721645 is about 154.9690538289.

The spelling of 3721645 in words is "three million, seven hundred twenty-one thousand, six hundred forty-five".