1221112211001 has 8 divisors (see below), whose sum is σ = 1628159738304. Its totient is φ = 814069745520.

The previous prime is 1221112210999. The next prime is 1221112211119. The reversal of 1221112211001 is 1001122111221.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1221112211001 - 2¹ = 1221112210999 is a prime.

It is a super-2 number, since 2×1221112211001² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221112251001) 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 7 ways as a sum of consecutive naturals, for example, 661365 + ... + 1696946.

It is an arithmetic number, because the mean of its divisors is an integer number (203519967288).

Almost surely, 2^{1221112211001} is an apocalyptic number.

It is an amenable number.

1221112211001 is a deficient number, since it is larger than the sum of its proper divisors (407047527303).

1221112211001 is a wasteful number, since it uses less digits than its factorization.

1221112211001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2530911.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 1221112211001 its reverse (1001122111221), we get a palindrome (2222234322222).

It can be divided in two parts, 122111221 and 1001, that multiplied together give a palindrome (122233332221).

The spelling of 1221112211001 in words is "one trillion, two hundred twenty-one billion, one hundred twelve million, two hundred eleven thousand, one".