6656420321237 has 2 divisors, whose sum is σ = 6656420321238. Its totient is φ = 6656420321236.

The previous prime is 6656420321227. The next prime is 6656420321311. The reversal of 6656420321237 is 7321230246566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6584309812081 + 72110509156 = 2565991^2 + 268534^2 .

It is a cyclic number.

It is not a de Polignac number, because 6656420321237 - 2³⁸ = 6381542414293 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 6656420321191 and 6656420321200.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6656420321227) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3328210160618 + 3328210160619.

It is an arithmetic number, because the mean of its divisors is an integer number (3328210160619).

Almost surely, 2^{6656420321237} is an apocalyptic number.

It is an amenable number.

6656420321237 is a deficient number, since it is larger than the sum of its proper divisors (1).

6656420321237 is an equidigital number, since it uses as much as digits as its factorization.

6656420321237 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2177280, while the sum is 47.

The spelling of 6656420321237 in words is "six trillion, six hundred fifty-six billion, four hundred twenty million, three hundred twenty-one thousand, two hundred thirty-seven".