6456840581 has 2 divisors, whose sum is σ = 6456840582. Its totient is φ = 6456840580.

The previous prime is 6456840527. The next prime is 6456840617. The reversal of 6456840581 is 1850486546.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 3963835681 + 2493004900 = 62959^2 + 49930^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6456840581 is a prime.

It is a super-2 number, since 2×6456840581² = 83381580576896835122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6456840781) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3228420290 + 3228420291.

It is an arithmetic number, because the mean of its divisors is an integer number (3228420291).

Almost surely, 2^6456840581 is an apocalyptic number.

It is an amenable number.

6456840581 is a deficient number, since it is larger than the sum of its proper divisors (1).

6456840581 is an equidigital number, since it uses as much as digits as its factorization.

6456840581 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 921600, while the sum is 47.

The square root of 6456840581 is about 80354.4683325078. The cubic root of 6456840581 is about 1862.1158122093.

The spelling of 6456840581 in words is "six billion, four hundred fifty-six million, eight hundred forty thousand, five hundred eighty-one".