7978969 has 4 divisors (see below), whose sum is σ = 8173620. Its totient is φ = 7784320.

The previous prime is 7978961. The next prime is 7978979. The reversal of 7978969 is 9698797.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 9698797 = 19 ⋅510463.

It can be written as a sum of positive squares in 2 ways, for example, as 211600 + 7767369 = 460^2 + 2787^2 .

It is a cyclic number.

It is not a de Polignac number, because 7978969 - 2³ = 7978961 is a prime.

It is a super-2 number, since 2×7978969² = 127327892605922, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7978961) 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, 97264 + ... + 97345.

It is an arithmetic number, because the mean of its divisors is an integer number (2043405).

Almost surely, 2^7978969 is an apocalyptic number.

It is an amenable number.

7978969 is a deficient number, since it is larger than the sum of its proper divisors (194651).

7978969 is a wasteful number, since it uses less digits than its factorization.

7978969 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 194650.

The product of its digits is 1714608, while the sum is 55.

The square root of 7978969 is about 2824.7068874487. The cubic root of 7978969 is about 199.8245878646.

The spelling of 7978969 in words is "seven million, nine hundred seventy-eight thousand, nine hundred sixty-nine".