65661520225205 has 16 divisors (see below), whose sum is σ = 79196493158640. Its totient is φ = 52260788439552.

The previous prime is 65661520225163. The next prime is 65661520225229. The reversal of 65661520225205 is 50252202516656.

It can be written as a sum of positive squares in 8 ways, for example, as 13385814947569 + 52275705277636 = 3658663^2 + 7230194^2 .

It is a cyclic number.

It is not a de Polignac number, because 65661520225205 - 2³² = 65657225257909 is a prime.

It is a super-2 number, since 2×65661520225205² (a number of 28 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 65661520225205.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 28149641 + ... + 30392849.

It is an arithmetic number, because the mean of its divisors is an integer number (4949780822415).

Almost surely, 2^{65661520225205} is an apocalyptic number.

It is an amenable number.

65661520225205 is a deficient number, since it is larger than the sum of its proper divisors (13534972933435).

65661520225205 is a wasteful number, since it uses less digits than its factorization.

65661520225205 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2273128.

The product of its (nonzero) digits is 2160000, while the sum is 47.

The spelling of 65661520225205 in words is "sixty-five trillion, six hundred sixty-one billion, five hundred twenty million, two hundred twenty-five thousand, two hundred five".