221540501 has 16 divisors (see below), whose sum is σ = 274512000. Its totient is φ = 174097728.

The previous prime is 221540479. The next prime is 221540533. The reversal of 221540501 is 105045122.

It is not a de Polignac number, because 221540501 - 2¹⁰ = 221539477 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221540591) 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 15 ways as a sum of consecutive naturals, for example, 5390 + ... + 21728.

It is an arithmetic number, because the mean of its divisors is an integer number (17157000).

Almost surely, 2^221540501 is an apocalyptic number.

It is an amenable number.

221540501 is a deficient number, since it is larger than the sum of its proper divisors (52971499).

221540501 is a wasteful number, since it uses less digits than its factorization.

221540501 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16508.

The product of its (nonzero) digits is 400, while the sum is 20.

The square root of 221540501 is about 14884.2366616498. The cubic root of 221540501 is about 605.0868449883.

Adding to 221540501 its reverse (105045122), we get a palindrome (326585623).

The spelling of 221540501 in words is "two hundred twenty-one million, five hundred forty thousand, five hundred one".