1221212110001 has 32 divisors (see below), whose sum is σ = 1437788620800. Its totient is φ = 1027504215360.

The previous prime is 1221212109947. The next prime is 1221212110033. The reversal of 1221212110001 is 1000112121221.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1221212110001 is a prime.

It is a super-2 number, since 2×1221212110001² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221212110501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 206555 + ... + 1576416.

It is an arithmetic number, because the mean of its divisors is an integer number (44930894400).

Almost surely, 2^{1221212110001} is an apocalyptic number.

It is an amenable number.

1221212110001 is a deficient number, since it is larger than the sum of its proper divisors (216576510799).

1221212110001 is a wasteful number, since it uses less digits than its factorization.

1221212110001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1783109.

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

Adding to 1221212110001 its reverse (1000112121221), we get a palindrome (2221324231222).

The spelling of 1221212110001 in words is "one trillion, two hundred twenty-one billion, two hundred twelve million, one hundred ten thousand, one".