1221201211123 has 4 divisors (see below), whose sum is σ = 1221203617920. Its totient is φ = 1221198804328.

The previous prime is 1221201211121. The next prime is 1221201211129. The reversal of 1221201211123 is 3211121021221.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1221201211123 - 2¹ = 1221201211121 is a prime.

It is a super-2 number, since 2×1221201211123² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1221201211123.

It is not an unprimeable number, because it can be changed into a prime (1221201211121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 112915 + ... + 1566892.

It is an arithmetic number, because the mean of its divisors is an integer number (305300904480).

Almost surely, 2^{1221201211123} is an apocalyptic number.

1221201211123 is a deficient number, since it is larger than the sum of its proper divisors (2406797).

1221201211123 is an equidigital number, since it uses as much as digits as its factorization.

1221201211123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2406796.

The product of its (nonzero) digits is 96, while the sum is 19.

Adding to 1221201211123 its reverse (3211121021221), we get a palindrome (4432322232344).

The spelling of 1221201211123 in words is "one trillion, two hundred twenty-one billion, two hundred one million, two hundred eleven thousand, one hundred twenty-three".