978942665 has 8 divisors (see below), whose sum is σ = 1182616200. Its totient is φ = 777897472.

The previous prime is 978942631. The next prime is 978942673. The reversal of 978942665 is 566249879.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3721 + 978938944 = 61^2 + 31288^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 978942665 - 2¹⁶ = 978877129 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 978942665.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 656264 + ... + 657753.

It is an arithmetic number, because the mean of its divisors is an integer number (147827025).

Almost surely, 2^978942665 is an apocalyptic number.

It is an amenable number.

978942665 is a deficient number, since it is larger than the sum of its proper divisors (203673535).

978942665 is a wasteful number, since it uses less digits than its factorization.

978942665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1314171.

The product of its digits is 6531840, while the sum is 56.

The square root of 978942665 is about 31288.0594636356. The cubic root of 978942665 is about 992.9310358248.

The spelling of 978942665 in words is "nine hundred seventy-eight million, nine hundred forty-two thousand, six hundred sixty-five".