3978855 has 16 divisors (see below), whose sum is σ = 7073760. Its totient is φ = 2121984.

The previous prime is 3978841. The next prime is 3978859. The reversal of 3978855 is 5588793.

It is not a de Polignac number, because 3978855 - 2⁵ = 3978823 is a prime.

It is a super-2 number, since 2×3978855² = 31662574222050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 3978855.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3978859) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14602 + ... + 14871.

It is an arithmetic number, because the mean of its divisors is an integer number (442110).

Almost surely, 2^3978855 is an apocalyptic number.

3978855 is a deficient number, since it is larger than the sum of its proper divisors (3094905).

3978855 is a wasteful number, since it uses less digits than its factorization.

3978855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 29487 (or 29481 counting only the distinct ones).

The product of its digits is 302400, while the sum is 45.

The square root of 3978855 is about 1994.7067453638. The cubic root of 3978855 is about 158.4598975724.

The spelling of 3978855 in words is "three million, nine hundred seventy-eight thousand, eight hundred fifty-five".