203165646121 has 9 divisors (see below), whose sum is σ = 203807262583. Its totient is φ = 202526047480.

The previous prime is 203165646091. The next prime is 203165646157. The reversal of 203165646121 is 121646561302.

The square root of 203165646121 is 450739.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 125981693721 + 77183952400 = 354939^2 + 277820^2 .

It is a de Polignac number, because none of the positive numbers 2^k-203165646121 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (203165656121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 215903511 + ... + 215904451.

Almost surely, 2^203165646121 is an apocalyptic number.

203165646121 is the 450739-th square number.

203165646121 is the 225370-th centered octagonal number.

It is an amenable number.

203165646121 is a deficient number, since it is larger than the sum of its proper divisors (641616462).

203165646121 is an frugal number, since it uses more digits than its factorization.

203165646121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2840 (or 1420 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 37.

The spelling of 203165646121 in words is "two hundred three billion, one hundred sixty-five million, six hundred forty-six thousand, one hundred twenty-one".