1221000000002 has 16 divisors (see below), whose sum is σ = 1850436419832. Its totient is φ = 604188234240.

The previous prime is 1220999999993. The next prime is 1221000000007. The reversal of 1221000000002 is 2000000001221.

It can be written as a sum of positive squares in 4 ways, for example, as 1154466440521 + 66533559481 = 1074461^2 + 257941^2 .

It is not an unprimeable number, because it can be changed into a prime (1221000000007) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8468588 + ... + 8611560.

Almost surely, 2^{1221000000002} is an apocalyptic number.

1221000000002 is a deficient number, since it is larger than the sum of its proper divisors (629436419830).

1221000000002 is a wasteful number, since it uses less digits than its factorization.

1221000000002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187093.

The product of its (nonzero) digits is 8, while the sum is 8.

Adding to 1221000000002 its reverse (2000000001221), we get a palindrome (3221000001223).

The spelling of 1221000000002 in words is "one trillion, two hundred twenty-one billion, two", and thus it is an aban number.