7978417 has 4 divisors (see below), whose sum is σ = 7984116. Its totient is φ = 7972720.

The previous prime is 7978409. The next prime is 7978429. The reversal of 7978417 is 7148797.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 7148797 = 137 ⋅52181.

It can be written as a sum of positive squares in 2 ways, for example, as 5125696 + 2852721 = 2264^2 + 1689^2 .

It is a cyclic number.

It is not a de Polignac number, because 7978417 - 2³ = 7978409 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7972417) 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, 867 + ... + 4087.

It is an arithmetic number, because the mean of its divisors is an integer number (1996029).

Almost surely, 2^7978417 is an apocalyptic number.

It is an amenable number.

7978417 is a deficient number, since it is larger than the sum of its proper divisors (5699).

7978417 is a wasteful number, since it uses less digits than its factorization.

7978417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5698.

The product of its digits is 98784, while the sum is 43.

The square root of 7978417 is about 2824.6091765057. The cubic root of 7978417 is about 199.8199796787.

The spelling of 7978417 in words is "seven million, nine hundred seventy-eight thousand, four hundred seventeen".