165661334025 has 24 divisors (see below), whose sum is σ = 298792807584. Its totient is φ = 80320646400.

The previous prime is 165661333949. The next prime is 165661334051. The reversal of 165661334025 is 520433166561.

It is not a de Polignac number, because 165661334025 - 2⁸ = 165661333769 is a prime.

It is a Curzon number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 100399984 + ... + 100401633.

It is an arithmetic number, because the mean of its divisors is an integer number (12449700316).

Almost surely, 2^165661334025 is an apocalyptic number.

165661334025 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

165661334025 is a deficient number, since it is larger than the sum of its proper divisors (133131473559).

165661334025 is a wasteful number, since it uses less digits than its factorization.

165661334025 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 200801641 (or 200801636 counting only the distinct ones).

The product of its (nonzero) digits is 388800, while the sum is 42.

The spelling of 165661334025 in words is "one hundred sixty-five billion, six hundred sixty-one million, three hundred thirty-four thousand, twenty-five".