2001212121111 has 64 divisors (see below), whose sum is σ = 3200380305408. Its totient is φ = 1087537385088.

The previous prime is 2001212121089. The next prime is 2001212121119. The reversal of 2001212121111 is 1111212121002.

It is a happy number.

It is not a de Polignac number, because 2001212121111 - 2¹¹ = 2001212119063 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001212121119) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 158229790 + ... + 158242436.

It is an arithmetic number, because the mean of its divisors is an integer number (50005942272).

Almost surely, 2^{2001212121111} is an apocalyptic number.

2001212121111 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

2001212121111 is a deficient number, since it is larger than the sum of its proper divisors (1199168184297).

2001212121111 is a wasteful number, since it uses less digits than its factorization.

2001212121111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14540.

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

Adding to 2001212121111 its reverse (1111212121002), we get a palindrome (3112424242113).

It can be divided in two parts, 200121 and 2121111, that added together give a palindrome (2321232).

The spelling of 2001212121111 in words is "two trillion, one billion, two hundred twelve million, one hundred twenty-one thousand, one hundred eleven".