1221110021001 has 32 divisors (see below), whose sum is σ = 1786659638400. Its totient is φ = 737196355584.

The previous prime is 1221110020997. The next prime is 1221110021057. The reversal of 1221110021001 is 1001200111221.

It is not a de Polignac number, because 1221110021001 - 2² = 1221110020997 is a prime.

It is a super-2 number, since 2×1221110021001² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1221110021801) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 24156585 + ... + 24207081.

It is an arithmetic number, because the mean of its divisors is an integer number (55833113700).

Almost surely, 2^{1221110021001} is an apocalyptic number.

It is an amenable number.

1221110021001 is a deficient number, since it is larger than the sum of its proper divisors (565549617399).

1221110021001 is a wasteful number, since it uses less digits than its factorization.

1221110021001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 62265.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 1221110021001 its reverse (1001200111221), we get a palindrome (2222310132222).

The spelling of 1221110021001 in words is "one trillion, two hundred twenty-one billion, one hundred ten million, twenty-one thousand, one".