3878821 has 8 divisors (see below), whose sum is σ = 4037120. Its totient is φ = 3723408.

The previous prime is 3878783. The next prime is 3878843. The reversal of 3878821 is 1288783.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 3878821 - 2¹¹ = 3876773 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a d-powerful number, because it can be written as 3¹³ + 8² + 7⁶ + 8⁴ + 8⁷ + 2¹⁶ + 1 .

It is a Duffinian number.

3878821 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3878221) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2260 + ... + 3586.

It is an arithmetic number, because the mean of its divisors is an integer number (504640).

Almost surely, 2^3878821 is an apocalyptic number.

It is an amenable number.

3878821 is a deficient number, since it is larger than the sum of its proper divisors (158299).

3878821 is a wasteful number, since it uses less digits than its factorization.

3878821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1443.

The product of its digits is 21504, while the sum is 37.

The square root of 3878821 is about 1969.4722643389. The cubic root of 3878821 is about 157.1206423930.

It can be divided in two parts, 38788 and 21, that added together give a square (38809 = 197²).

The spelling of 3878821 in words is "three million, eight hundred seventy-eight thousand, eight hundred twenty-one".