7640861 has 2 divisors, whose sum is σ = 7640862. Its totient is φ = 7640860.

The previous prime is 7640827. The next prime is 7640873. The reversal of 7640861 is 1680467.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6728836 + 912025 = 2594^2 + 955^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-7640861 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (7640821) by changing a digit.

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

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3820430 + 3820431.

It is an arithmetic number, because the mean of its divisors is an integer number (3820431).

Almost surely, 2^7640861 is an apocalyptic number.

It is an amenable number.

7640861 is a deficient number, since it is larger than the sum of its proper divisors (1).

7640861 is an equidigital number, since it uses as much as digits as its factorization.

7640861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 7640861 is about 2764.2107372630. The cubic root of 7640861 is about 196.9612384765.

The spelling of 7640861 in words is "seven million, six hundred forty thousand, eight hundred sixty-one".