3978740 has 12 divisors (see below), whose sum is σ = 8355396. Its totient is φ = 1591488.

The previous prime is 3978739. The next prime is 3978743. The reversal of 3978740 is 478793.

It can be written as a sum of positive squares in 2 ways, for example, as 1532644 + 2446096 = 1238^2 + 1564^2 .

It is a junction number, because it is equal to n+sod(n) for n = 3978694 and 3978703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3978743) 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, 99449 + ... + 99488.

It is an arithmetic number, because the mean of its divisors is an integer number (696283).

Almost surely, 2^3978740 is an apocalyptic number.

It is an amenable number.

3978740 is an abundant number, since it is smaller than the sum of its proper divisors (4376656).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3978740 is a wasteful number, since it uses less digits than its factorization.

3978740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198946 (or 198944 counting only the distinct ones).

The product of its (nonzero) digits is 42336, while the sum is 38.

The square root of 3978740 is about 1994.6779188631. The cubic root of 3978740 is about 158.4583709134.

The spelling of 3978740 in words is "three million, nine hundred seventy-eight thousand, seven hundred forty".