7981613 has 4 divisors (see below), whose sum is σ = 8009148. Its totient is φ = 7954080.

The previous prime is 7981591. The next prime is 7981627. The reversal of 7981613 is 3161897.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7823209 + 158404 = 2797^2 + 398^2 .

It is a cyclic number.

It is not a de Polignac number, because 7981613 - 2¹² = 7977517 is a prime.

It is a super-2 number, since 2×7981613² = 127412292163538, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7981013) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13328 + ... + 13913.

It is an arithmetic number, because the mean of its divisors is an integer number (2002287).

Almost surely, 2^7981613 is an apocalyptic number.

It is an amenable number.

7981613 is a deficient number, since it is larger than the sum of its proper divisors (27535).

7981613 is a wasteful number, since it uses less digits than its factorization.

7981613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27534.

The product of its digits is 9072, while the sum is 35.

The square root of 7981613 is about 2825.1748618448. The cubic root of 7981613 is about 199.8466574604.

The spelling of 7981613 in words is "seven million, nine hundred eighty-one thousand, six hundred thirteen".