221428593 has 32 divisors (see below), whose sum is σ = 337276800. Its totient is φ = 143520768.

The previous prime is 221428589. The next prime is 221428607. The reversal of 221428593 is 395824122.

It is a happy number.

221428593 is a `hidden beast` number, since 2 + 21 + 42 + 8 + 593 = 666.

It is not a de Polignac number, because 221428593 - 2² = 221428589 is a prime.

It is not an unprimeable number, because it can be changed into a prime (221428513) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 153805 + ... + 155237.

It is an arithmetic number, because the mean of its divisors is an integer number (10539900).

Almost surely, 2^221428593 is an apocalyptic number.

It is an amenable number.

221428593 is a deficient number, since it is larger than the sum of its proper divisors (115848207).

221428593 is a wasteful number, since it uses less digits than its factorization.

221428593 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1598 (or 1592 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 221428593 is about 14880.4769076801. The cubic root of 221428593 is about 604.9849441874.

The spelling of 221428593 in words is "two hundred twenty-one million, four hundred twenty-eight thousand, five hundred ninety-three".