1221222131 has 16 divisors (see below), whose sum is σ = 1312899840. Its totient is φ = 1132391520.

The previous prime is 1221222127. The next prime is 1221222139. The reversal of 1221222131 is 1312221221.

It is a cyclic number.

It is not a de Polignac number, because 1221222131 - 2² = 1221222127 is a prime.

It is a super-2 number, since 2×1221222131² = 2982766986488362322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221222139) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 505316 + ... + 507726.

It is an arithmetic number, because the mean of its divisors is an integer number (82056240).

Almost surely, 2^1221222131 is an apocalyptic number.

1221222131 is a deficient number, since it is larger than the sum of its proper divisors (91677709).

1221222131 is a wasteful number, since it uses less digits than its factorization.

1221222131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2986.

The product of its digits is 96, while the sum is 17.

The square root of 1221222131 is about 34945.9887683837. The cubic root of 1221222131 is about 1068.8864097924.

Adding to 1221222131 its reverse (1312221221), we get a palindrome (2533443352).

It can be divided in two parts, 12212 and 22131, that added together give a palindrome (34343).

The spelling of 1221222131 in words is "one billion, two hundred twenty-one million, two hundred twenty-two thousand, one hundred thirty-one".