121457345125561 has 4 divisors (see below), whose sum is σ = 123748993146852. Its totient is φ = 119165697104272.

The previous prime is 121457345125559. The next prime is 121457345125579. The reversal of 121457345125561 is 165521543754121.

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

It can be written as a sum of positive squares in 2 ways, for example, as 49625262030400 + 71832083095161 = 7044520^2 + 8475381^2 .

It is a cyclic number.

It is not a de Polignac number, because 121457345125561 - 2¹ = 121457345125559 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 121457345125499 and 121457345125508.

It is not an unprimeable number, because it can be changed into a prime (121457345125541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1145824010566 + ... + 1145824010671.

It is an arithmetic number, because the mean of its divisors is an integer number (30937248286713).

Almost surely, 2^{121457345125561} is an apocalyptic number.

It is an amenable number.

121457345125561 is a deficient number, since it is larger than the sum of its proper divisors (2291648021291).

121457345125561 is an equidigital number, since it uses as much as digits as its factorization.

121457345125561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2291648021290.

The product of its digits is 5040000, while the sum is 52.

Adding to 121457345125561 its reverse (165521543754121), we get a palindrome (286978888879682).

The spelling of 121457345125561 in words is "one hundred twenty-one trillion, four hundred fifty-seven billion, three hundred forty-five million, one hundred twenty-five thousand, five hundred sixty-one".