7981647 has 8 divisors (see below), whose sum is σ = 10673280. Its totient is φ = 5305560.

The previous prime is 7981639. The next prime is 7981661. The reversal of 7981647 is 7461897.

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

It is not a de Polignac number, because 7981647 - 2³ = 7981639 is a prime.

7981647 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 7981599 and 7981608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7981627) 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, 2629 + ... + 4782.

It is an arithmetic number, because the mean of its divisors is an integer number (1334160).

Almost surely, 2^7981647 is an apocalyptic number.

7981647 is a deficient number, since it is larger than the sum of its proper divisors (2691633).

7981647 is a wasteful number, since it uses less digits than its factorization.

7981647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7773.

The product of its digits is 84672, while the sum is 42.

The square root of 7981647 is about 2825.1808791651. The cubic root of 7981647 is about 199.8469412283.

The spelling of 7981647 in words is "seven million, nine hundred eighty-one thousand, six hundred forty-seven".