9978641 has 8 divisors (see below), whose sum is σ = 10307880. Its totient is φ = 9659664.

The previous prime is 9978637. The next prime is 9978649. The reversal of 9978641 is 1468799.

It can be written as a sum of positive squares in 4 ways, for example, as 7102225 + 2876416 = 2665^2 + 1696^2 .

It is not a de Polignac number, because 9978641 - 2² = 9978637 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 9978592 and 9978601.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9978649) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50555 + ... + 50751.

It is an arithmetic number, because the mean of its divisors is an integer number (1288485).

Almost surely, 2^9978641 is an apocalyptic number.

It is an amenable number.

9978641 is a deficient number, since it is larger than the sum of its proper divisors (329239).

9978641 is an frugal number, since it uses more digits than its factorization.

9978641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308 (or 234 counting only the distinct ones).

The product of its digits is 108864, while the sum is 44.

The square root of 9978641 is about 3158.8987004967. The cubic root of 9978641 is about 215.2899710974.

The spelling of 9978641 in words is "nine million, nine hundred seventy-eight thousand, six hundred forty-one".