121751556503 has 4 divisors (see below), whose sum is σ = 124342015200. Its totient is φ = 119161097808.

The previous prime is 121751556491. The next prime is 121751556523. The reversal of 121751556503 is 305655157121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 305655157121 = 286771 ⋅1065851.

It is a cyclic number.

It is not a de Polignac number, because 121751556503 - 2²² = 121747362199 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 (121751556523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1295229278 + ... + 1295229371.

It is an arithmetic number, because the mean of its divisors is an integer number (31085503800).

Almost surely, 2^121751556503 is an apocalyptic number.

121751556503 is a deficient number, since it is larger than the sum of its proper divisors (2590458697).

121751556503 is an equidigital number, since it uses as much as digits as its factorization.

121751556503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2590458696.

The product of its (nonzero) digits is 157500, while the sum is 41.

The spelling of 121751556503 in words is "one hundred twenty-one billion, seven hundred fifty-one million, five hundred fifty-six thousand, five hundred three".