165561235232653 has 4 divisors (see below), whose sum is σ = 178296714865948. Its totient is φ = 152825755599360.

The previous prime is 165561235232651. The next prime is 165561235232671. The reversal of 165561235232653 is 356232532165561.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 53603293316329 + 111957941916324 = 7321427^2 + 10581018^2 .

It is a cyclic number.

It is not a de Polignac number, because 165561235232653 - 2¹ = 165561235232651 is a prime.

It is a super-2 number, since 2×165561235232653² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 165561235232594 and 165561235232603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165561235232651) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6367739816628 + ... + 6367739816653.

It is an arithmetic number, because the mean of its divisors is an integer number (44574178716487).

Almost surely, 2^{165561235232653} is an apocalyptic number.

165561235232653 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

165561235232653 is a deficient number, since it is larger than the sum of its proper divisors (12735479633295).

165561235232653 is a wasteful number, since it uses less digits than its factorization.

165561235232653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12735479633294.

The product of its digits is 29160000, while the sum is 55.

The spelling of 165561235232653 in words is "one hundred sixty-five trillion, five hundred sixty-one billion, two hundred thirty-five million, two hundred thirty-two thousand, six hundred fifty-three".