165551001 has 16 divisors (see below), whose sum is σ = 275202048. Its totient is φ = 86000400.

The previous prime is 165550951. The next prime is 165551017. The reversal of 165551001 is 100155561.

It is not a de Polignac number, because 165551001 - 2¹⁰ = 165549977 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (165551041) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 358105 + ... + 358566.

It is an arithmetic number, because the mean of its divisors is an integer number (17200128).

Almost surely, 2^165551001 is an apocalyptic number.

165551001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

165551001 is a deficient number, since it is larger than the sum of its proper divisors (109651047).

165551001 is a wasteful number, since it uses less digits than its factorization.

165551001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 716692.

The product of its (nonzero) digits is 750, while the sum is 24.

The square root of 165551001 is about 12866.6623877368. The cubic root of 165551001 is about 549.0905089977.

The spelling of 165551001 in words is "one hundred sixty-five million, five hundred fifty-one thousand, one".