221221461 has 4 divisors (see below), whose sum is σ = 294961952. Its totient is φ = 147480972.

The previous prime is 221221457. The next prime is 221221499. The reversal of 221221461 is 164122122.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 221221461 - 2² = 221221457 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 (221221421) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 36870241 + ... + 36870246.

It is an arithmetic number, because the mean of its divisors is an integer number (73740488).

Almost surely, 2^221221461 is an apocalyptic number.

It is an amenable number.

221221461 is a deficient number, since it is larger than the sum of its proper divisors (73740491).

221221461 is an equidigital number, since it uses as much as digits as its factorization.

221221461 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73740490.

The product of its digits is 384, while the sum is 21.

The square root of 221221461 is about 14873.5154217152. The cubic root of 221221461 is about 604.7962440234.

Adding to 221221461 its reverse (164122122), we get a palindrome (385343583).

The spelling of 221221461 in words is "two hundred twenty-one million, two hundred twenty-one thousand, four hundred sixty-one".