3661221465569 has 2 divisors, whose sum is σ = 3661221465570. Its totient is φ = 3661221465568.

The previous prime is 3661221465547. The next prime is 3661221465599. The reversal of 3661221465569 is 9655641221663.

It is a happy number.

3661221465569 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3078663270544 + 582558195025 = 1754612^2 + 763255^2 .

It is a cyclic number.

It is not a de Polignac number, because 3661221465569 - 2¹² = 3661221461473 is a prime.

It is a super-2 number, since 2×3661221465569² (a number of 26 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (3661221465509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1830610732784 + 1830610732785.

It is an arithmetic number, because the mean of its divisors is an integer number (1830610732785).

Almost surely, 2^{3661221465569} is an apocalyptic number.

It is an amenable number.

3661221465569 is a deficient number, since it is larger than the sum of its proper divisors (1).

3661221465569 is an equidigital number, since it uses as much as digits as its factorization.

3661221465569 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 13996800, while the sum is 56.

The spelling of 3661221465569 in words is "three trillion, six hundred sixty-one billion, two hundred twenty-one million, four hundred sixty-five thousand, five hundred sixty-nine".