1221200012 has 12 divisors (see below), whose sum is σ = 2164152480. Its totient is φ = 602870736.

The previous prime is 1221200011. The next prime is 1221200017. The reversal of 1221200012 is 2100021221.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 1221199966 and 1221200002.

It is not an unprimeable number, because it can be changed into a prime (1221200011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1931963 + ... + 1932594.

It is an arithmetic number, because the mean of its divisors is an integer number (180346040).

Almost surely, 2^1221200012 is an apocalyptic number.

It is an amenable number.

1221200012 is a deficient number, since it is larger than the sum of its proper divisors (942952468).

1221200012 is a wasteful number, since it uses less digits than its factorization.

1221200012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3864640 (or 3864638 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 1221200012 is about 34945.6722928605. The cubic root of 1221200012 is about 1068.8799564643.

Adding to 1221200012 its reverse (2100021221), we get a palindrome (3321221233).

The spelling of 1221200012 in words is "one billion, two hundred twenty-one million, two hundred thousand, twelve".