221432641 has 4 divisors (see below), whose sum is σ = 221516800. Its totient is φ = 221348484.

The previous prime is 221432621. The next prime is 221432657. The reversal of 221432641 is 146234122.

It is a happy number.

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 221432641 - 2²¹ = 219335489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221432621) 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, 38001 + ... + 43438.

It is an arithmetic number, because the mean of its divisors is an integer number (55379200).

Almost surely, 2^221432641 is an apocalyptic number.

It is an amenable number.

221432641 is a deficient number, since it is larger than the sum of its proper divisors (84159).

221432641 is an equidigital number, since it uses as much as digits as its factorization.

221432641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84158.

The product of its digits is 2304, while the sum is 25.

The square root of 221432641 is about 14880.6129242044. The cubic root of 221432641 is about 604.9886307997.

Adding to 221432641 its reverse (146234122), we get a palindrome (367666763).

The spelling of 221432641 in words is "two hundred twenty-one million, four hundred thirty-two thousand, six hundred forty-one".