1217822221 has 32 divisors (see below), whose sum is σ = 1591704576. Its totient is φ = 904176000.

The previous prime is 1217822173. The next prime is 1217822237. The reversal of 1217822221 is 1222287121.

It is not a de Polignac number, because 1217822221 - 2¹⁵ = 1217789453 is a prime.

It is a super-2 number, since 2×1217822221² = 2966181923922745682, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 1217822221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1217822261) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 131266 + ... + 140236.

It is an arithmetic number, because the mean of its divisors is an integer number (49740768).

Almost surely, 2^1217822221 is an apocalyptic number.

1217822221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1217822221 is a deficient number, since it is larger than the sum of its proper divisors (373882355).

1217822221 is a wasteful number, since it uses less digits than its factorization.

1217822221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9073.

The product of its digits is 1792, while the sum is 28.

The square root of 1217822221 is about 34897.3096527512. The cubic root of 1217822221 is about 1067.8935532062.

The spelling of 1217822221 in words is "one billion, two hundred seventeen million, eight hundred twenty-two thousand, two hundred twenty-one".