121312355545 has 4 divisors (see below), whose sum is σ = 145574826660. Its totient is φ = 97049884432.

The previous prime is 121312355539. The next prime is 121312355551. The reversal of 121312355545 is 545553213121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 545553213121 = 7 ⋅77936173303.

It is an interprime number because it is at equal distance from previous prime (121312355539) and next prime (121312355551).

It can be written as a sum of positive squares in 2 ways, for example, as 52360422976 + 68951932569 = 228824^2 + 262587^2 .

It is a cyclic number.

It is not a de Polignac number, because 121312355545 - 2¹¹ = 121312353497 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12131235550 + ... + 12131235559.

It is an arithmetic number, because the mean of its divisors is an integer number (36393706665).

Almost surely, 2^121312355545 is an apocalyptic number.

It is an amenable number.

121312355545 is a deficient number, since it is larger than the sum of its proper divisors (24262471115).

121312355545 is an equidigital number, since it uses as much as digits as its factorization.

121312355545 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24262471114.

The product of its digits is 90000, while the sum is 37.

Adding to 121312355545 its reverse (545553213121), we get a palindrome (666865568666).

The spelling of 121312355545 in words is "one hundred twenty-one billion, three hundred twelve million, three hundred fifty-five thousand, five hundred forty-five".