1211021212121 has 16 divisors (see below), whose sum is σ = 1431769371648. Its totient is φ = 1002354609600.

The previous prime is 1211021212103. The next prime is 1211021212123. The reversal of 1211021212121 is 1212121201121.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1211021212121 is a prime.

1211021212121 is a modest number, since divided by 21212121 gives 12110 as remainder.

It is a self number, because there is not a number n which added to its sum of digits gives 1211021212121.

It is not an unprimeable number, because it can be changed into a prime (1211021212123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5952830 + ... + 6152903.

It is an arithmetic number, because the mean of its divisors is an integer number (89485585728).

Almost surely, 2^{1211021212121} is an apocalyptic number.

It is an amenable number.

1211021212121 is a deficient number, since it is larger than the sum of its proper divisors (220748159527).

1211021212121 is a wasteful number, since it uses less digits than its factorization.

1211021212121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12106232.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 1211021212121 its reverse (1212121201121), we get a palindrome (2423142413242).

The spelling of 1211021212121 in words is "one trillion, two hundred eleven billion, twenty-one million, two hundred twelve thousand, one hundred twenty-one".