201215021 has 12 divisors (see below), whose sum is σ = 242139420. Its totient is φ = 166521600.

The previous prime is 201215011. The next prime is 201215033. The reversal of 201215021 is 120512102.

It can be written as a sum of positive squares in 2 ways, for example, as 167702500 + 33512521 = 12950^2 + 5789^2 .

It is not a de Polignac number, because 201215021 - 2²⁶ = 134106157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 201214987 and 201215005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201215011) 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, 69380 + ... + 72221.

It is an arithmetic number, because the mean of its divisors is an integer number (20178285).

Almost surely, 2^201215021 is an apocalyptic number.

It is an amenable number.

201215021 is a deficient number, since it is larger than the sum of its proper divisors (40924399).

201215021 is a wasteful number, since it uses less digits than its factorization.

201215021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141644 (or 141637 counting only the distinct ones).

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 201215021 is about 14185.0280577798. The cubic root of 201215021 is about 585.9854052130.

Adding to 201215021 its reverse (120512102), we get a palindrome (321727123).

The spelling of 201215021 in words is "two hundred one million, two hundred fifteen thousand, twenty-one".