64557221 has 8 divisors (see below), whose sum is σ = 66885888. Its totient is φ = 62244000.

The previous prime is 64557203. The next prime is 64557253. The reversal of 64557221 is 12275546.

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-64557221 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (64557271) 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, 5006 + ... + 12416.

It is an arithmetic number, because the mean of its divisors is an integer number (8360736).

Almost surely, 2^64557221 is an apocalyptic number.

It is an amenable number.

64557221 is a deficient number, since it is larger than the sum of its proper divisors (2328667).

64557221 is a wasteful number, since it uses less digits than its factorization.

64557221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7723.

The product of its digits is 16800, while the sum is 32.

The square root of 64557221 is about 8034.7508362114. The cubic root of 64557221 is about 401.1575241966.

The spelling of 64557221 in words is "sixty-four million, five hundred fifty-seven thousand, two hundred twenty-one".