20165121 has 12 divisors (see below), whose sum is σ = 30132180. Its totient is φ = 12979680.

The previous prime is 20165081. The next prime is 20165129. The reversal of 20165121 is 12156102.

It can be written as a sum of positive squares in 2 ways, for example, as 13068225 + 7096896 = 3615^2 + 2664^2 .

It is not a de Polignac number, because 20165121 - 2¹⁸ = 19902977 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 20165094 and 20165103.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20165129) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38370 + ... + 38891.

It is an arithmetic number, because the mean of its divisors is an integer number (2511015).

Almost surely, 2^20165121 is an apocalyptic number.

It is an amenable number.

20165121 is a deficient number, since it is larger than the sum of its proper divisors (9967059).

20165121 is a wasteful number, since it uses less digits than its factorization.

20165121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 77296 (or 77293 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 20165121 is about 4490.5590965937. The cubic root of 20165121 is about 272.1867274991.

The spelling of 20165121 in words is "twenty million, one hundred sixty-five thousand, one hundred twenty-one".