3978813 has 4 divisors (see below), whose sum is σ = 5305088. Its totient is φ = 2652540.

The previous prime is 3978811. The next prime is 3978817. The reversal of 3978813 is 3188793.

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: 3188793 = 3 ⋅1062931.

It is not a de Polignac number, because 3978813 - 2¹ = 3978811 is a prime.

It is an Ulam number.

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 (3978811) 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, 663133 + ... + 663138.

It is an arithmetic number, because the mean of its divisors is an integer number (1326272).

Almost surely, 2^3978813 is an apocalyptic number.

It is an amenable number.

3978813 is a deficient number, since it is larger than the sum of its proper divisors (1326275).

3978813 is a wasteful number, since it uses less digits than its factorization.

3978813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1326274.

The product of its digits is 36288, while the sum is 39.

The square root of 3978813 is about 1994.6962174727. The cubic root of 3978813 is about 158.4593400134.

The spelling of 3978813 in words is "three million, nine hundred seventy-eight thousand, eight hundred thirteen".