221542541 has 8 divisors (see below), whose sum is σ = 241910400. Its totient is φ = 201212640.

The previous prime is 221542511. The next prime is 221542553. The reversal of 221542541 is 145245122.

221542541 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-221542541 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 221542541.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221542501) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3500 + ... + 21338.

It is an arithmetic number, because the mean of its divisors is an integer number (30238800).

Almost surely, 2^221542541 is an apocalyptic number.

It is an amenable number.

221542541 is a deficient number, since it is larger than the sum of its proper divisors (20367859).

221542541 is a wasteful number, since it uses less digits than its factorization.

221542541 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18979.

The product of its digits is 3200, while the sum is 26.

The square root of 221542541 is about 14884.3051903675. The cubic root of 221542541 is about 605.0887022460.

Adding to 221542541 its reverse (145245122), we get a palindrome (366787663).

The spelling of 221542541 in words is "two hundred twenty-one million, five hundred forty-two thousand, five hundred forty-one".