7978489 has 4 divisors (see below), whose sum is σ = 8001700. Its totient is φ = 7955280.

The previous prime is 7978471. The next prime is 7978519. The reversal of 7978489 is 9848797.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6786025 + 1192464 = 2605^2 + 1092^2 .

It is a cyclic number.

It is not a de Polignac number, because 7978489 - 2¹⁹ = 7454201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7978409) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11082 + ... + 11779.

It is an arithmetic number, because the mean of its divisors is an integer number (2000425).

Almost surely, 2^7978489 is an apocalyptic number.

It is an amenable number.

7978489 is a deficient number, since it is larger than the sum of its proper divisors (23211).

7978489 is a wasteful number, since it uses less digits than its factorization.

7978489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23210.

The product of its digits is 1016064, while the sum is 52.

The square root of 7978489 is about 2824.6219216030. The cubic root of 7978489 is about 199.8205807585.

The spelling of 7978489 in words is "seven million, nine hundred seventy-eight thousand, four hundred eighty-nine".