1221021212210 has 16 divisors (see below), whose sum is σ = 2198379994776. Its totient is φ = 488288082048.

The previous prime is 1221021212183. The next prime is 1221021212221. The reversal of 1221021212210 is 122121201221.

It can be written as a sum of positive squares in 4 ways, for example, as 674916470089 + 546104742121 = 821533^2 + 738989^2 .

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 15007757 + ... + 15088896.

Almost surely, 2^{1221021212210} is an apocalyptic number.

1221021212210 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1221021212210 is a deficient number, since it is larger than the sum of its proper divisors (977358782566).

1221021212210 is a wasteful number, since it uses less digits than its factorization.

1221021212210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30100717.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 1221021212210 its reverse (122121201221), we get a palindrome (1343142413431).

The spelling of 1221021212210 in words is "one trillion, two hundred twenty-one billion, twenty-one million, two hundred twelve thousand, two hundred ten".