6663557 has 2 divisors, whose sum is σ = 6663558. Its totient is φ = 6663556.

The previous prime is 6663539. The next prime is 6663593. The reversal of 6663557 is 7553666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5527201 + 1136356 = 2351^2 + 1066^2 .

It is a cyclic number.

It is not a de Polignac number, because 6663557 - 2⁶ = 6663493 is a prime.

It is a super-3 number, since 3×6663557³ (a number of 21 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 6663557.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6663257) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3331778 + 3331779.

It is an arithmetic number, because the mean of its divisors is an integer number (3331779).

Almost surely, 2^6663557 is an apocalyptic number.

It is an amenable number.

6663557 is a deficient number, since it is larger than the sum of its proper divisors (1).

6663557 is an equidigital number, since it uses as much as digits as its factorization.

6663557 is an evil number, because the sum of its binary digits is even.

The product of its digits is 113400, while the sum is 38.

The square root of 6663557 is about 2581.3866428724. The cubic root of 6663557 is about 188.1779381414.

The spelling of 6663557 in words is "six million, six hundred sixty-three thousand, five hundred fifty-seven".