121722721503 has 4 divisors (see below), whose sum is σ = 162296962008. Its totient is φ = 81148481000.

The previous prime is 121722721499. The next prime is 121722721529. The reversal of 121722721503 is 305127227121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 305127227121 = 3 ⋅101709075707.

It is a cyclic number.

It is not a de Polignac number, because 121722721503 - 2² = 121722721499 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121722721553) 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, 20287120248 + ... + 20287120253.

It is an arithmetic number, because the mean of its divisors is an integer number (40574240502).

Almost surely, 2^121722721503 is an apocalyptic number.

121722721503 is a deficient number, since it is larger than the sum of its proper divisors (40574240505).

121722721503 is an equidigital number, since it uses as much as digits as its factorization.

121722721503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40574240504.

The product of its (nonzero) digits is 11760, while the sum is 33.

Adding to 121722721503 its reverse (305127227121), we get a palindrome (426849948624).

The spelling of 121722721503 in words is "one hundred twenty-one billion, seven hundred twenty-two million, seven hundred twenty-one thousand, five hundred three".