1566501616441 has 2 divisors, whose sum is σ = 1566501616442. Its totient is φ = 1566501616440.

The previous prime is 1566501616439. The next prime is 1566501616583. The reversal of 1566501616441 is 1446161056651.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1129322788416 + 437178828025 = 1062696^2 + 661195^2 .

It is a cyclic number.

It is not a de Polignac number, because 1566501616441 - 2¹ = 1566501616439 is a prime.

Together with 1566501616439, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 1566501616391 and 1566501616400.

It is not a weakly prime, because it can be changed into another prime (1566501616411) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 783250808220 + 783250808221.

It is an arithmetic number, because the mean of its divisors is an integer number (783250808221).

Almost surely, 2^{1566501616441} is an apocalyptic number.

It is an amenable number.

1566501616441 is a deficient number, since it is larger than the sum of its proper divisors (1).

1566501616441 is an equidigital number, since it uses as much as digits as its factorization.

1566501616441 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 518400, while the sum is 46.

The spelling of 1566501616441 in words is "one trillion, five hundred sixty-six billion, five hundred one million, six hundred sixteen thousand, four hundred forty-one".