1217427221 has 8 divisors (see below), whose sum is σ = 1261549080. Its totient is φ = 1173448192.

The previous prime is 1217427193. The next prime is 1217427241. The reversal of 1217427221 is 1227247121.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 28143025 + 1189284196 = 5305^2 + 34486^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1217427221 - 2⁶ = 1217427157 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (29).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1217427241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18200 + ... + 52593.

It is an arithmetic number, because the mean of its divisors is an integer number (157693635).

Almost surely, 2^1217427221 is an apocalyptic number.

It is an amenable number.

1217427221 is a deficient number, since it is larger than the sum of its proper divisors (44121859).

1217427221 is an equidigital number, since it uses as much as digits as its factorization.

1217427221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71415.

The product of its digits is 3136, while the sum is 29.

The square root of 1217427221 is about 34891.6497317051. The cubic root of 1217427221 is about 1067.7780838162.

The spelling of 1217427221 in words is "one billion, two hundred seventeen million, four hundred twenty-seven thousand, two hundred twenty-one".