7981686 has 32 divisors (see below), whose sum is σ = 17971200. Its totient is φ = 2625480.

The previous prime is 7981661. The next prime is 7981711. The reversal of 7981686 is 6861897.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (7981661) and next prime (7981711).

It is a super-2 number, since 2×7981686² = 127414622805192, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3331 + ... + 5201.

It is an arithmetic number, because the mean of its divisors is an integer number (561600).

Almost surely, 2^7981686 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 7981686, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (8985600).

7981686 is an abundant number, since it is smaller than the sum of its proper divisors (9989514).

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

7981686 is a wasteful number, since it uses less digits than its factorization.

7981686 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1961 (or 1955 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 7981686 is about 2825.1877813696. The cubic root of 7981686 is about 199.8472667258.

The spelling of 7981686 in words is "seven million, nine hundred eighty-one thousand, six hundred eighty-six".