221065641 has 12 divisors (see below), whose sum is σ = 319449780. Its totient is φ = 147315840.

The previous prime is 221065633. The next prime is 221065643. The reversal of 221065641 is 146560122.

221065641 is a `hidden beast` number, since 2 + 2 + 1 + 0 + 656 + 4 + 1 = 666.

221065641 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 154480041 + 66585600 = 12429^2 + 8160^2 .

It is not a de Polignac number, because 221065641 - 2³ = 221065633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221065643) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 31765 + ... + 38093.

It is an arithmetic number, because the mean of its divisors is an integer number (26620815).

Almost surely, 2^221065641 is an apocalyptic number.

It is an amenable number.

221065641 is a deficient number, since it is larger than the sum of its proper divisors (98384139).

221065641 is a wasteful number, since it uses less digits than its factorization.

221065641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10216 (or 10213 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 221065641 is about 14868.2763291513. The cubic root of 221065641 is about 604.6542121651.

The spelling of 221065641 in words is "two hundred twenty-one million, sixty-five thousand, six hundred forty-one".