165561235232663 has 4 divisors (see below), whose sum is σ = 165561296921328. Its totient is φ = 165561173544000.

The previous prime is 165561235232651. The next prime is 165561235232671. The reversal of 165561235232663 is 366232532165561.

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

It is a cyclic number.

It is not a de Polignac number, because 165561235232663 - 2¹² = 165561235228567 is a prime.

It is a super-2 number, since 2×165561235232663² (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 = 165561235232599 and 165561235232608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165561235232863) 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, 26626331 + ... + 32250332.

It is an arithmetic number, because the mean of its divisors is an integer number (41390324230332).

Almost surely, 2^{165561235232663} is an apocalyptic number.

165561235232663 is a deficient number, since it is larger than the sum of its proper divisors (61688665).

165561235232663 is an equidigital number, since it uses as much as digits as its factorization.

165561235232663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 61688664.

The product of its digits is 34992000, while the sum is 56.

The spelling of 165561235232663 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 sixty-three".