1221111021000 has 192 divisors, whose sum is σ = 4125478331520. Its totient is φ = 300581049600.

The previous prime is 1221111020959. The next prime is 1221111021001. The reversal of 1221111021000 is 1201111221.

It is a super-2 number, since 2×1221111021000² (a number of 25 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (1221111021001) 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 47 ways as a sum of consecutive naturals, for example, 697252 + ... + 1711251.

It is an arithmetic number, because the mean of its divisors is an integer number (21486866310).

Almost surely, 2^{1221111021000} is an apocalyptic number.

1221111021000 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221111021000 is an abundant number, since it is smaller than the sum of its proper divisors (2904367310520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1221111021000 is a wasteful number, since it uses less digits than its factorization.

1221111021000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2408553 (or 2408526 counting only the distinct ones).

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

Adding to 1221111021000 its reverse (1201111221), we get a palindrome (1222312132221).

The spelling of 1221111021000 in words is "one trillion, two hundred twenty-one billion, one hundred eleven million, twenty-one thousand".