7978147 has 4 divisors (see below), whose sum is σ = 7985016. Its totient is φ = 7971280.

The previous prime is 7978099. The next prime is 7978169. The reversal of 7978147 is 7418797.

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: 7418797 = 19 ⋅390463.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7978147 is a prime.

It is a Duffinian number.

7978147 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (7978247) 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, 1213 + ... + 4174.

It is an arithmetic number, because the mean of its divisors is an integer number (1996254).

Almost surely, 2^7978147 is an apocalyptic number.

7978147 is a deficient number, since it is larger than the sum of its proper divisors (6869).

7978147 is a wasteful number, since it uses less digits than its factorization.

7978147 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6868.

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

The square root of 7978147 is about 2824.5613818786. The cubic root of 7978147 is about 199.8177255973.

The spelling of 7978147 in words is "seven million, nine hundred seventy-eight thousand, one hundred forty-seven".