6491557 has 2 divisors, whose sum is σ = 6491558. Its totient is φ = 6491556.

The previous prime is 6491549. The next prime is 6491561. The reversal of 6491557 is 7551946.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 6120676 + 370881 = 2474^2 + 609^2 .

It is a cyclic number.

It is not a de Polignac number, because 6491557 - 2³ = 6491549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6491257) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3245778 + 3245779.

It is an arithmetic number, because the mean of its divisors is an integer number (3245779).

Almost surely, 2^6491557 is an apocalyptic number.

It is an amenable number.

6491557 is a deficient number, since it is larger than the sum of its proper divisors (1).

6491557 is an equidigital number, since it uses as much as digits as its factorization.

6491557 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 37800, while the sum is 37.

The square root of 6491557 is about 2547.8534102259. The cubic root of 6491557 is about 186.5447187482.

The spelling of 6491557 in words is "six million, four hundred ninety-one thousand, five hundred fifty-seven".