121340421543 has 32 divisors (see below), whose sum is σ = 183255321600. Its totient is φ = 70741641600.

The previous prime is 121340421533. The next prime is 121340421551. The reversal of 121340421543 is 345124043121.

It is not a de Polignac number, because 121340421543 - 2⁸ = 121340421287 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 121340421543.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121340421533) 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 31 ways as a sum of consecutive naturals, for example, 25413 + ... + 493281.

It is an arithmetic number, because the mean of its divisors is an integer number (5726728800).

Almost surely, 2^121340421543 is an apocalyptic number.

121340421543 is a deficient number, since it is larger than the sum of its proper divisors (61914900057).

121340421543 is a wasteful number, since it uses less digits than its factorization.

121340421543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 468183.

The product of its (nonzero) digits is 11520, while the sum is 30.

Adding to 121340421543 its reverse (345124043121), we get a palindrome (466464464664).

The spelling of 121340421543 in words is "one hundred twenty-one billion, three hundred forty million, four hundred twenty-one thousand, five hundred forty-three".