3765821 has 4 divisors (see below), whose sum is σ = 3780732. Its totient is φ = 3750912.

The previous prime is 3765799. The next prime is 3765829. The reversal of 3765821 is 1285673.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 3463321 + 302500 = 1861^2 + 550^2 .

It is a cyclic number.

It is not a de Polignac number, because 3765821 - 2⁶ = 3765757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3765829) 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, 7070 + ... + 7583.

It is an arithmetic number, because the mean of its divisors is an integer number (945183).

Almost surely, 2^3765821 is an apocalyptic number.

It is an amenable number.

3765821 is a deficient number, since it is larger than the sum of its proper divisors (14911).

3765821 is a wasteful number, since it uses less digits than its factorization.

3765821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14910.

The product of its digits is 10080, while the sum is 32.

The square root of 3765821 is about 1940.5723382549. The cubic root of 3765821 is about 155.5798055354.

The spelling of 3765821 in words is "three million, seven hundred sixty-five thousand, eight hundred twenty-one".