3978161 has 4 divisors (see below), whose sum is σ = 4339824. Its totient is φ = 3616500.

The previous prime is 3978113. The next prime is 3978167. The reversal of 3978161 is 1618793.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1618793 = 11 ⋅147163.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3978161 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3978167) 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, 180815 + ... + 180836.

It is an arithmetic number, because the mean of its divisors is an integer number (1084956).

Almost surely, 2^3978161 is an apocalyptic number.

It is an amenable number.

3978161 is a deficient number, since it is larger than the sum of its proper divisors (361663).

3978161 is a wasteful number, since it uses less digits than its factorization.

3978161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 361662.

The product of its digits is 9072, while the sum is 35.

The square root of 3978161 is about 1994.5327773692. The cubic root of 3978161 is about 158.4506840706.

It can be divided in two parts, 397 and 8161, that added together give a palindrome (8558).

The spelling of 3978161 in words is "three million, nine hundred seventy-eight thousand, one hundred sixty-one".