3661221465625 has 12 divisors (see below), whose sum is σ = 4576233938220. Its totient is φ = 2928977170000.

The previous prime is 3661221465623. The next prime is 3661221465659. The reversal of 3661221465625 is 5265641221663.

It can be written as a sum of positive squares in 6 ways, for example, as 3552218481289 + 109002984336 = 1884733^2 + 330156^2 .

It is not a de Polignac number, because 3661221465625 - 2¹ = 3661221465623 is a prime.

It is not an unprimeable number, because it can be changed into a prime (3661221465623) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 585792310 + ... + 585798559.

It is an arithmetic number, because the mean of its divisors is an integer number (381352828185).

Almost surely, 2^{3661221465625} is an apocalyptic number.

It is an amenable number.

3661221465625 is a deficient number, since it is larger than the sum of its proper divisors (915012472595).

3661221465625 is an frugal number, since it uses more digits than its factorization.

3661221465625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1171590894 (or 1171590874 counting only the distinct ones).

The product of its digits is 3110400, while the sum is 49.

The spelling of 3661221465625 in words is "three trillion, six hundred sixty-one billion, two hundred twenty-one million, four hundred sixty-five thousand, six hundred twenty-five".