7840013 has 2 divisors, whose sum is σ = 7840014. Its totient is φ = 7840012.

The previous prime is 7839961. The next prime is 7840031. The reversal of 7840013 is 3100487.

It is a happy number.

Together with next prime (7840031) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 7739524 + 100489 = 2782^2 + 317^2 .

It is a cyclic number.

It is not a de Polignac number, because 7840013 - 2¹² = 7835917 is a prime.

It is a super-2 number, since 2×7840013² = 122931607680338, which contains 22 as substring.

It is an Ulam number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7840073) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3920006 + 3920007.

It is an arithmetic number, because the mean of its divisors is an integer number (3920007).

Almost surely, 2^7840013 is an apocalyptic number.

It is an amenable number.

7840013 is a deficient number, since it is larger than the sum of its proper divisors (1).

7840013 is an equidigital number, since it uses as much as digits as its factorization.

7840013 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 672, while the sum is 23.

The square root of 7840013 is about 2800.0023214276. The cubic root of 7840013 is about 198.6577874781.

The spelling of 7840013 in words is "seven million, eight hundred forty thousand, thirteen".