121321001243 has 18 divisors (see below), whose sum is σ = 137331495756. Its totient is φ = 107119467312.

The previous prime is 121321001237. The next prime is 121321001261. The reversal of 121321001243 is 342100123121.

It is not a de Polignac number, because 121321001243 - 2¹⁴ = 121320984859 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121321001273) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 589121 + ... + 767922.

It is an arithmetic number, because the mean of its divisors is an integer number (7629527542).

Almost surely, 2^121321001243 is an apocalyptic number.

121321001243 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

121321001243 is a deficient number, since it is larger than the sum of its proper divisors (16010494513).

121321001243 is a wasteful number, since it uses less digits than its factorization.

121321001243 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1357115 (or 1357079 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 20.

Adding to 121321001243 its reverse (342100123121), we get a palindrome (463421124364).

The spelling of 121321001243 in words is "one hundred twenty-one billion, three hundred twenty-one million, one thousand, two hundred forty-three".