557221666 has 4 divisors (see below), whose sum is σ = 835832502. Its totient is φ = 278610832.

The previous prime is 557221663. The next prime is 557221669. The reversal of 557221666 is 666122755.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 666122755 = 5 ⋅133224551.

It is an interprime number because it is at equal distance from previous prime (557221663) and next prime (557221669).

It can be written as a sum of positive squares in only one way, i.e., 354757225 + 202464441 = 18835^2 + 14229^2 .

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (557221663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 139305415 + ... + 139305418.

Almost surely, 2^557221666 is an apocalyptic number.

557221666 is a deficient number, since it is larger than the sum of its proper divisors (278610836).

557221666 is a wasteful number, since it uses less digits than its factorization.

557221666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 278610835.

The product of its digits is 151200, while the sum is 40.

The square root of 557221666 is about 23605.5431202080. The cubic root of 557221666 is about 822.8916676265.

The spelling of 557221666 in words is "five hundred fifty-seven million, two hundred twenty-one thousand, six hundred sixty-six".