165656551 has 8 divisors (see below), whose sum is σ = 175595904. Its totient is φ = 155738880.

The previous prime is 165656549. The next prime is 165656567. The reversal of 165656551 is 155656561.

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

It is a cyclic number.

It is not a de Polignac number, because 165656551 - 2¹ = 165656549 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 (165656951) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11931 + ... + 21763.

It is an arithmetic number, because the mean of its divisors is an integer number (21949488).

Almost surely, 2^165656551 is an apocalyptic number.

165656551 is a deficient number, since it is larger than the sum of its proper divisors (9939353).

165656551 is an equidigital number, since it uses as much as digits as its factorization.

165656551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10841.

The product of its digits is 135000, while the sum is 40.

The square root of 165656551 is about 12870.7634194713. The cubic root of 165656551 is about 549.2071783628.

The spelling of 165656551 in words is "one hundred sixty-five million, six hundred fifty-six thousand, five hundred fifty-one".