9978581 has 8 divisors (see below), whose sum is σ = 10375680. Its totient is φ = 9585072.

The previous prime is 9978557. The next prime is 9978583. The reversal of 9978581 is 1858799.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-9978581 is a prime.

It is a super-2 number, since 2×9978581² = 199144157547122, 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 (9978583) 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, 5696 + ... + 7238.

It is an arithmetic number, because the mean of its divisors is an integer number (1296960).

Almost surely, 2^9978581 is an apocalyptic number.

It is an amenable number.

9978581 is a deficient number, since it is larger than the sum of its proper divisors (397099).

9978581 is a wasteful number, since it uses less digits than its factorization.

9978581 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1795.

The product of its digits is 181440, while the sum is 47.

The square root of 9978581 is about 3158.8892035018. The cubic root of 9978581 is about 215.2895395949.

The spelling of 9978581 in words is "nine million, nine hundred seventy-eight thousand, five hundred eighty-one".