3721815 has 32 divisors (see below), whose sum is σ = 6969600. Its totient is φ = 1879200.

The previous prime is 3721813. The next prime is 3721847. The reversal of 3721815 is 5181273.

It is not a de Polignac number, because 3721815 - 2¹ = 3721813 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3721811) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1840 + ... + 3290.

It is an arithmetic number, because the mean of its divisors is an integer number (217800).

Almost surely, 2^3721815 is an apocalyptic number.

3721815 is a deficient number, since it is larger than the sum of its proper divisors (3247785).

3721815 is a wasteful number, since it uses less digits than its factorization.

3721815 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1484 (or 1478 counting only the distinct ones).

The product of its digits is 1680, while the sum is 27.

The square root of 3721815 is about 1929.2006116524. The cubic root of 3721815 is about 154.9714133892.

It can be divided in two parts, 372 and 1815, that added together give a 7-th power (2187 = 3⁷).

The spelling of 3721815 in words is "three million, seven hundred twenty-one thousand, eight hundred fifteen".