3718821 has 4 divisors (see below), whose sum is σ = 4958432. Its totient is φ = 2479212.

The previous prime is 3718807. The next prime is 3718831. The reversal of 3718821 is 1288173.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 3718821 - 2⁵ = 3718789 is a prime.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3718831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 619801 + ... + 619806.

It is an arithmetic number, because the mean of its divisors is an integer number (1239608).

Almost surely, 2^3718821 is an apocalyptic number.

It is an amenable number.

3718821 is a deficient number, since it is larger than the sum of its proper divisors (1239611).

3718821 is a wasteful number, since it uses less digits than its factorization.

3718821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1239610.

The product of its digits is 2688, while the sum is 30.

The square root of 3718821 is about 1928.4244864656. The cubic root of 3718821 is about 154.9298468521.

The spelling of 3718821 in words is "three million, seven hundred eighteen thousand, eight hundred twenty-one".