1221020002 has 64 divisors (see below), whose sum is σ = 2121292800. Its totient is φ = 523837440.

The previous prime is 1221019979. The next prime is 1221020069. The reversal of 1221020002 is 2000201221.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1313874 + ... + 1314802.

It is an arithmetic number, because the mean of its divisors is an integer number (33145200).

Almost surely, 2^1221020002 is an apocalyptic number.

1221020002 is a deficient number, since it is larger than the sum of its proper divisors (900272798).

1221020002 is a wasteful number, since it uses less digits than its factorization.

1221020002 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1051.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 1221020002 is about 34943.0966286619. The cubic root of 1221020002 is about 1068.8274347551.

Adding to 1221020002 its reverse (2000201221), we get a palindrome (3221221223).

The spelling of 1221020002 in words is "one billion, two hundred twenty-one million, twenty thousand, two".