1221111212 has 6 divisors (see below), whose sum is σ = 2136944628. Its totient is φ = 610555604.

The previous prime is 1221111167. The next prime is 1221111253. The reversal of 1221111212 is 2121111221.

It is a super-2 number, since 2×1221111212² = 2982225184144217888, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 152638898 + ... + 152638905.

It is an arithmetic number, because the mean of its divisors is an integer number (356157438).

Almost surely, 2^1221111212 is an apocalyptic number.

It is an amenable number.

1221111212 is a deficient number, since it is larger than the sum of its proper divisors (915833416).

1221111212 is a wasteful number, since it uses less digits than its factorization.

1221111212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 305277807 (or 305277805 counting only the distinct ones).

The product of its digits is 16, while the sum is 14.

The square root of 1221111212 is about 34944.4017261707. The cubic root of 1221111212 is about 1068.8540478390.

Adding to 1221111212 its reverse (2121111221), we get a palindrome (3342222433).

Subtracting 1221111212 from its reverse (2121111221), we obtain a palindrome (900000009).

The spelling of 1221111212 in words is "one billion, two hundred twenty-one million, one hundred eleven thousand, two hundred twelve".