221621275 has 6 divisors (see below), whose sum is σ = 274810412. Its totient is φ = 177297000.

The previous prime is 221621273. The next prime is 221621293. The reversal of 221621275 is 572126122.

It is not a de Polignac number, because 221621275 - 2¹ = 221621273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (221621273) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4432401 + ... + 4432450.

Almost surely, 2^221621275 is an apocalyptic number.

221621275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

221621275 is a deficient number, since it is larger than the sum of its proper divisors (53189137).

221621275 is an equidigital number, since it uses as much as digits as its factorization.

221621275 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8864861 (or 8864856 counting only the distinct ones).

The product of its digits is 3360, while the sum is 28.

The square root of 221621275 is about 14886.9498219078. The cubic root of 221621275 is about 605.1603745774.

Adding to 221621275 its reverse (572126122), we get a palindrome (793747397).

The spelling of 221621275 in words is "two hundred twenty-one million, six hundred twenty-one thousand, two hundred seventy-five".