165663225 has 240 divisors, whose sum is σ = 403307520. Its totient is φ = 65318400.

The previous prime is 165663221. The next prime is 165663241. The reversal of 165663225 is 522366561.

It is a happy number.

165663225 is a `hidden beast` number, since 16 + 5 + 6 + 632 + 2 + 5 = 666.

It is not a de Polignac number, because 165663225 - 2² = 165663221 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 165663225.

It is not an unprimeable number, because it can be changed into a prime (165663221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 239 ways as a sum of consecutive naturals, for example, 5343960 + ... + 5343990.

It is an arithmetic number, because the mean of its divisors is an integer number (1680448).

Almost surely, 2^165663225 is an apocalyptic number.

165663225 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

165663225 is an abundant number, since it is smaller than the sum of its proper divisors (237644295).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

165663225 is a wasteful number, since it uses less digits than its factorization.

165663225 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102 (or 88 counting only the distinct ones).

The product of its digits is 64800, while the sum is 36.

The square root of 165663225 is about 12871.0226866399. The cubic root of 165663225 is about 549.2145537819.

It can be divided in two parts, 16566 and 3225, that added together give a palindrome (19791).

The spelling of 165663225 in words is "one hundred sixty-five million, six hundred sixty-three thousand, two hundred twenty-five".