201521145 has 96 divisors (see below), whose sum is σ = 406713600. Its totient is φ = 83349504.

The previous prime is 201521141. The next prime is 201521161. The reversal of 201521145 is 541125102.

It is not a de Polignac number, because 201521145 - 2² = 201521141 is a prime.

It is a super-2 number, since 2×201521145² = 81221543764222050, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (201521141) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 879891 + ... + 880119.

It is an arithmetic number, because the mean of its divisors is an integer number (4236600).

Almost surely, 2^201521145 is an apocalyptic number.

It is an amenable number.

201521145 is an abundant number, since it is smaller than the sum of its proper divisors (205192455).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

201521145 is a wasteful number, since it uses less digits than its factorization.

201521145 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 307 (or 290 counting only the distinct ones).

The product of its (nonzero) digits is 400, while the sum is 21.

The square root of 201521145 is about 14195.8143478985. The cubic root of 201521145 is about 586.2824229700.

Adding to 201521145 its reverse (541125102), we get a palindrome (742646247).

The spelling of 201521145 in words is "two hundred one million, five hundred twenty-one thousand, one hundred forty-five".