165925551 has 32 divisors (see below), whose sum is σ = 247484160. Its totient is φ = 98035200.

The previous prime is 165925541. The next prime is 165925553. The reversal of 165925551 is 155529561.

It is not a de Polignac number, because 165925551 - 2¹⁰ = 165924527 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165925553) 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 31 ways as a sum of consecutive naturals, for example, 279511 + ... + 280103.

It is an arithmetic number, because the mean of its divisors is an integer number (7733880).

Almost surely, 2^165925551 is an apocalyptic number.

165925551 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

165925551 is a deficient number, since it is larger than the sum of its proper divisors (81558609).

165925551 is a wasteful number, since it uses less digits than its factorization.

165925551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 807.

The product of its digits is 67500, while the sum is 39.

The square root of 165925551 is about 12881.2092211873. The cubic root of 165925551 is about 549.5042927542.

The spelling of 165925551 in words is "one hundred sixty-five million, nine hundred twenty-five thousand, five hundred fifty-one".