3661221465565 has 16 divisors (see below), whose sum is σ = 4455499167360. Its totient is φ = 2887624411840.

The previous prime is 3661221465547. The next prime is 3661221465569. The reversal of 3661221465565 is 5655641221663.

It is not a de Polignac number, because 3661221465565 - 2¹³ = 3661221457373 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3661221465569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11148087 + ... + 11471803.

It is an arithmetic number, because the mean of its divisors is an integer number (278468697960).

Almost surely, 2^{3661221465565} is an apocalyptic number.

It is an amenable number.

3661221465565 is a deficient number, since it is larger than the sum of its proper divisors (794277701795).

3661221465565 is a wasteful number, since it uses less digits than its factorization.

3661221465565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355652.

The product of its digits is 7776000, while the sum is 52.

The spelling of 3661221465565 in words is "three trillion, six hundred sixty-one billion, two hundred twenty-one million, four hundred sixty-five thousand, five hundred sixty-five".