9978667 has 4 divisors (see below), whose sum is σ = 10503880. Its totient is φ = 9453456.

The previous prime is 9978659. The next prime is 9978719. The reversal of 9978667 is 7668799.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7668799 = 19 ⋅403621.

It is a cyclic number.

It is not a de Polignac number, because 9978667 - 2³ = 9978659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (9978607) 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, 262578 + ... + 262615.

It is an arithmetic number, because the mean of its divisors is an integer number (2625970).

Almost surely, 2^9978667 is an apocalyptic number.

9978667 is a deficient number, since it is larger than the sum of its proper divisors (525213).

9978667 is a wasteful number, since it uses less digits than its factorization.

9978667 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 525212.

The product of its digits is 1143072, while the sum is 52.

The square root of 9978667 is about 3158.9028158524. The cubic root of 9978667 is about 215.2901580812.

The spelling of 9978667 in words is "nine million, nine hundred seventy-eight thousand, six hundred sixty-seven".