1221212101001 has 2 divisors, whose sum is σ = 1221212101002. Its totient is φ = 1221212101000.

The previous prime is 1221212100973. The next prime is 1221212101073. The reversal of 1221212101001 is 1001012121221.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1218648197776 + 2563903225 = 1103924^2 + 50635^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221212101001 is a prime.

It is not a weakly prime, because it can be changed into another prime (1221212101601) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 610606050500 + 610606050501.

It is an arithmetic number, because the mean of its divisors is an integer number (610606050501).

Almost surely, 2^{1221212101001} is an apocalyptic number.

It is an amenable number.

1221212101001 is a deficient number, since it is larger than the sum of its proper divisors (1).

1221212101001 is an equidigital number, since it uses as much as digits as its factorization.

1221212101001 is an odious number, because the sum of its binary digits is odd.

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

Adding to 1221212101001 its reverse (1001012121221), we get a palindrome (2222224222222).

The spelling of 1221212101001 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, one hundred one thousand, one".