201555215121 has 12 divisors (see below), whose sum is σ = 291002796528. Its totient is φ = 124033978224.

The previous prime is 201555215119. The next prime is 201555215189. The reversal of 201555215121 is 121512555102.

It is not a de Polignac number, because 201555215121 - 2¹ = 201555215119 is a prime.

It is not an unprimeable number, because it can be changed into a prime (201555215821) 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 11 ways as a sum of consecutive naturals, for example, 198771895 + ... + 198772908.

It is an arithmetic number, because the mean of its divisors is an integer number (24250233044).

Almost surely, 2^201555215121 is an apocalyptic number.

It is an amenable number.

201555215121 is a deficient number, since it is larger than the sum of its proper divisors (89447581407).

201555215121 is a wasteful number, since it uses less digits than its factorization.

201555215121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 397544832 (or 397544819 counting only the distinct ones).

The product of its (nonzero) digits is 5000, while the sum is 30.

The spelling of 201555215121 in words is "two hundred one billion, five hundred fifty-five million, two hundred fifteen thousand, one hundred twenty-one".