165550551 has 8 divisors (see below), whose sum is σ = 220894464. Its totient is φ = 110286840.

The previous prime is 165550549. The next prime is 165550603. The reversal of 165550551 is 155055561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 165550551 - 2¹ = 165550549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165550051) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 15055 + ... + 23616.

It is an arithmetic number, because the mean of its divisors is an integer number (27611808).

Almost surely, 2^165550551 is an apocalyptic number.

165550551 is a deficient number, since it is larger than the sum of its proper divisors (55343913).

165550551 is a wasteful number, since it uses less digits than its factorization.

165550551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40101.

The product of its (nonzero) digits is 18750, while the sum is 33.

The square root of 165550551 is about 12866.6449006724. The cubic root of 165550551 is about 549.0900114854.

The spelling of 165550551 in words is "one hundred sixty-five million, five hundred fifty thousand, five hundred fifty-one".