3721665 has 16 divisors (see below), whose sum is σ = 5986368. Its totient is φ = 1974336.

The previous prime is 3721631. The next prime is 3721673. The reversal of 3721665 is 5661273.

It is not a de Polignac number, because 3721665 - 2⁷ = 3721537 is a prime.

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, 2859 + ... + 3951.

It is an arithmetic number, because the mean of its divisors is an integer number (374148).

Almost surely, 2^3721665 is an apocalyptic number.

It is an amenable number.

3721665 is a deficient number, since it is larger than the sum of its proper divisors (2264703).

3721665 is a wasteful number, since it uses less digits than its factorization.

3721665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1328.

The product of its digits is 7560, while the sum is 30.

The square root of 3721665 is about 1929.1617350549. The cubic root of 3721665 is about 154.9693314279.

The spelling of 3721665 in words is "three million, seven hundred twenty-one thousand, six hundred sixty-five".