3721840 has 20 divisors (see below), whose sum is σ = 8653464. Its totient is φ = 1488704.

The previous prime is 3721813. The next prime is 3721847. The reversal of 3721840 is 481273.

It is a tau number, because it is divible by the number of its divisors (20).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3721847) 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, 23182 + ... + 23341.

Almost surely, 2^3721840 is an apocalyptic number.

It is an amenable number.

3721840 is an abundant number, since it is smaller than the sum of its proper divisors (4931624).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3721840 is a wasteful number, since it uses less digits than its factorization.

3721840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46536 (or 46530 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 3721840 is about 1929.2070910092. The cubic root of 3721840 is about 154.9717603773.

The spelling of 3721840 in words is "three million, seven hundred twenty-one thousand, eight hundred forty".