121243554431 has 4 divisors (see below), whose sum is σ = 125154636864. Its totient is φ = 117332472000.

The previous prime is 121243554427. The next prime is 121243554437. The reversal of 121243554431 is 134455342121.

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 121243554431 - 2² = 121243554427 is a prime.

It is a super-2 number, since 2×121243554431² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121243554391 and 121243554400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121243554437) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1955541170 + ... + 1955541231.

It is an arithmetic number, because the mean of its divisors is an integer number (31288659216).

Almost surely, 2^121243554431 is an apocalyptic number.

121243554431 is a deficient number, since it is larger than the sum of its proper divisors (3911082433).

121243554431 is an equidigital number, since it uses as much as digits as its factorization.

121243554431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3911082432.

The product of its digits is 57600, while the sum is 35.

Adding to 121243554431 its reverse (134455342121), we get a palindrome (255698896552).

The spelling of 121243554431 in words is "one hundred twenty-one billion, two hundred forty-three million, five hundred fifty-four thousand, four hundred thirty-one".