165650551 has 4 divisors (see below), whose sum is σ = 180709704. Its totient is φ = 150591400.

The previous prime is 165650521. The next prime is 165650561. The reversal of 165650551 is 155056561.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 155056561 = 11 ⋅14096051.

It is a cyclic number.

It is not a de Polignac number, because 165650551 - 2⁷ = 165650423 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165650521) 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 3 ways as a sum of consecutive naturals, for example, 7529560 + ... + 7529581.

It is an arithmetic number, because the mean of its divisors is an integer number (45177426).

Almost surely, 2^165650551 is an apocalyptic number.

165650551 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

165650551 is a deficient number, since it is larger than the sum of its proper divisors (15059153).

165650551 is a wasteful number, since it uses less digits than its factorization.

165650551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15059152.

The product of its (nonzero) digits is 22500, while the sum is 34.

The square root of 165650551 is about 12870.5303309537. The cubic root of 165650551 is about 549.2005476101.

The spelling of 165650551 in words is "one hundred sixty-five million, six hundred fifty thousand, five hundred fifty-one".