221201251 has 4 divisors (see below), whose sum is σ = 221517504. Its totient is φ = 220885000.

The previous prime is 221201203. The next prime is 221201257. The reversal of 221201251 is 152102122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 152102122 = 2 ⋅76051061.

It is a cyclic number.

It is not a de Polignac number, because 221201251 - 2⁹ = 221200739 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221201257) 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, 157075 + ... + 158476.

It is an arithmetic number, because the mean of its divisors is an integer number (55379376).

Almost surely, 2^221201251 is an apocalyptic number.

221201251 is a deficient number, since it is larger than the sum of its proper divisors (316253).

221201251 is an equidigital number, since it uses as much as digits as its factorization.

221201251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 316252.

The product of its (nonzero) digits is 80, while the sum is 16.

The square root of 221201251 is about 14872.8360106605. The cubic root of 221201251 is about 604.7778261233. Note that the first 3 decimals are identical.

Adding to 221201251 its reverse (152102122), we get a palindrome (373303373).

The spelling of 221201251 in words is "two hundred twenty-one million, two hundred one thousand, two hundred fifty-one".