165506650500521 has 16 divisors (see below), whose sum is σ = 181103392937088. Its totient is φ = 150001873190400.

The previous prime is 165506650500481. The next prime is 165506650500563. The reversal of 165506650500521 is 125005056605561.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-165506650500521 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (165506650500221) 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, 13331420 + ... + 22555266.

It is an arithmetic number, because the mean of its divisors is an integer number (11318962058568).

Almost surely, 2^{165506650500521} is an apocalyptic number.

165506650500521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

165506650500521 is a deficient number, since it is larger than the sum of its proper divisors (15596742436567).

165506650500521 is a wasteful number, since it uses less digits than its factorization.

165506650500521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9228832.

The product of its (nonzero) digits is 1350000, while the sum is 47.

The spelling of 165506650500521 in words is "one hundred sixty-five trillion, five hundred six billion, six hundred fifty million, five hundred thousand, five hundred twenty-one".