7978986 has 20 divisors (see below), whose sum is σ = 17879202. Its totient is φ = 2659608.

The previous prime is 7978981. The next prime is 7979009. The reversal of 7978986 is 6898797.

It can be written as a sum of positive squares in only one way, i.e., 7733961 + 245025 = 2781^2 + 495^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (7978981) 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 9 ways as a sum of consecutive naturals, for example, 24465 + ... + 24788.

Almost surely, 2^7978986 is an apocalyptic number.

7978986 is an abundant number, since it is smaller than the sum of its proper divisors (9900216).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7978986 is a wasteful number, since it uses less digits than its factorization.

7978986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49267 (or 49258 counting only the distinct ones).

The product of its digits is 1524096, while the sum is 54.

The square root of 7978986 is about 2824.7098966089. The cubic root of 7978986 is about 199.8247297800.

The spelling of 7978986 in words is "seven million, nine hundred seventy-eight thousand, nine hundred eighty-six".