3978406 has 4 divisors (see below), whose sum is σ = 5967612. Its totient is φ = 1989202.

The previous prime is 3978349. The next prime is 3978421. The reversal of 3978406 is 6048793.

It is a semiprime because it is the product of two primes.

It is a nialpdrome in base 9.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 994600 + ... + 994603.

It is an arithmetic number, because the mean of its divisors is an integer number (1491903).

Almost surely, 2^3978406 is an apocalyptic number.

3978406 is a deficient number, since it is larger than the sum of its proper divisors (1989206).

3978406 is a wasteful number, since it uses less digits than its factorization.

3978406 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1989205.

The product of its (nonzero) digits is 36288, while the sum is 37.

The square root of 3978406 is about 1994.5941943162. The cubic root of 3978406 is about 158.4539367980.

The spelling of 3978406 in words is "three million, nine hundred seventy-eight thousand, four hundred six".