221221466 has 4 divisors (see below), whose sum is σ = 331832202. Its totient is φ = 110610732.

The previous prime is 221221457. The next prime is 221221499. The reversal of 221221466 is 664122122.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 664122122 = 2 ⋅332061061.

It can be written as a sum of positive squares in only one way, i.e., 150577441 + 70644025 = 12271^2 + 8405^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 55305365 + ... + 55305368.

Almost surely, 2^221221466 is an apocalyptic number.

221221466 is a deficient number, since it is larger than the sum of its proper divisors (110610736).

221221466 is a wasteful number, since it uses less digits than its factorization.

221221466 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110610735.

The product of its digits is 2304, while the sum is 26.

The square root of 221221466 is about 14873.5155897992. The cubic root of 221221466 is about 604.7962485799.

Adding to 221221466 its reverse (664122122), we get a palindrome (885343588).

The spelling of 221221466 in words is "two hundred twenty-one million, two hundred twenty-one thousand, four hundred sixty-six".