121421155503 has 4 divisors (see below), whose sum is σ = 161894874008. Its totient is φ = 80947437000.

The previous prime is 121421155481. The next prime is 121421155511. The reversal of 121421155503 is 305551124121.

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

It is not a de Polignac number, because 121421155503 - 2⁶ = 121421155439 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121421155553) 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 3 ways as a sum of consecutive naturals, for example, 20236859248 + ... + 20236859253.

It is an arithmetic number, because the mean of its divisors is an integer number (40473718502).

Almost surely, 2^121421155503 is an apocalyptic number.

121421155503 is a deficient number, since it is larger than the sum of its proper divisors (40473718505).

121421155503 is an equidigital number, since it uses as much as digits as its factorization.

121421155503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40473718504.

The product of its (nonzero) digits is 6000, while the sum is 30.

Adding to 121421155503 its reverse (305551124121), we get a palindrome (426972279624).

The spelling of 121421155503 in words is "one hundred twenty-one billion, four hundred twenty-one million, one hundred fifty-five thousand, five hundred three".