6618358228561 has 2 divisors, whose sum is σ = 6618358228562. Its totient is φ = 6618358228560.

The previous prime is 6618358228543. The next prime is 6618358228583. The reversal of 6618358228561 is 1658228538166.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3744166950225 + 2874191278336 = 1934985^2 + 1695344^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-6618358228561 is a prime.

It is a super-2 number, since 2×6618358228561² (a number of 26 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 6618358228561.

It is not a weakly prime, because it can be changed into another prime (6618358220561) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3309179114280 + 3309179114281.

It is an arithmetic number, because the mean of its divisors is an integer number (3309179114281).

Almost surely, 2^{6618358228561} is an apocalyptic number.

It is an amenable number.

6618358228561 is a deficient number, since it is larger than the sum of its proper divisors (1).

6618358228561 is an equidigital number, since it uses as much as digits as its factorization.

6618358228561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 33177600, while the sum is 61.

The spelling of 6618358228561 in words is "six trillion, six hundred eighteen billion, three hundred fifty-eight million, two hundred twenty-eight thousand, five hundred sixty-one".