221541001 has 4 divisors (see below), whose sum is σ = 241681104. Its totient is φ = 201400900.

The previous prime is 221540993. The next prime is 221541029. The reversal of 221541001 is 100145122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221541001 - 2³ = 221540993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221541101) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10070035 + ... + 10070056.

It is an arithmetic number, because the mean of its divisors is an integer number (60420276).

Almost surely, 2^221541001 is an apocalyptic number.

It is an amenable number.

221541001 is a deficient number, since it is larger than the sum of its proper divisors (20140103).

221541001 is a wasteful number, since it uses less digits than its factorization.

221541001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20140102.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 221541001 is about 14884.2534579333. The cubic root of 221541001 is about 605.0873001996.

Adding to 221541001 its reverse (100145122), we get a palindrome (321686123).

The spelling of 221541001 in words is "two hundred twenty-one million, five hundred forty-one thousand, one".