121555275251 has 4 divisors (see below), whose sum is σ = 124520038104. Its totient is φ = 118590512400.

The previous prime is 121555275229. The next prime is 121555275263. The reversal of 121555275251 is 152572555121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 152572555121 = 7 ⋅21796079303.

It is a cyclic number.

It is not a de Polignac number, because 121555275251 - 2³⁰ = 120481533427 is a prime.

It is a super-2 number, since 2×121555275251² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (41), and also a Moran number because the ratio is a prime number: 2964762811 = 121555275251 / (1 + 2 + 1 + 5 + 5 + 5 + 2 + 7 + 5 + 2 + 5 + 1).

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121555275199 and 121555275208.

It is not an unprimeable number, because it can be changed into a prime (121554275251) 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, 1482381365 + ... + 1482381446.

It is an arithmetic number, because the mean of its divisors is an integer number (31130009526).

Almost surely, 2^121555275251 is an apocalyptic number.

121555275251 is a deficient number, since it is larger than the sum of its proper divisors (2964762853).

121555275251 is an equidigital number, since it uses as much as digits as its factorization.

121555275251 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2964762852.

The product of its digits is 175000, while the sum is 41.

The spelling of 121555275251 in words is "one hundred twenty-one billion, five hundred fifty-five million, two hundred seventy-five thousand, two hundred fifty-one".