1566511266601 has 2 divisors, whose sum is σ = 1566511266602. Its totient is φ = 1566511266600.

The previous prime is 1566511266563. The next prime is 1566511266611. The reversal of 1566511266601 is 1066621156651.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1546453909225 + 20057357376 = 1243565^2 + 141624^2 .

It is a cyclic number.

It is not a de Polignac number, because 1566511266601 - 2¹⁷ = 1566511135529 is a prime.

It is not a weakly prime, because it can be changed into another prime (1566511266611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 783255633300 + 783255633301.

It is an arithmetic number, because the mean of its divisors is an integer number (783255633301).

Almost surely, 2^{1566511266601} is an apocalyptic number.

It is an amenable number.

1566511266601 is a deficient number, since it is larger than the sum of its proper divisors (1).

1566511266601 is an equidigital number, since it uses as much as digits as its factorization.

1566511266601 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 388800, while the sum is 46.

The spelling of 1566511266601 in words is "one trillion, five hundred sixty-six billion, five hundred eleven million, two hundred sixty-six thousand, six hundred one".