121220261257 has 2 divisors, whose sum is σ = 121220261258. Its totient is φ = 121220261256.

The previous prime is 121220261221. The next prime is 121220261287. The reversal of 121220261257 is 752162022121.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 120198116416 + 1022144841 = 346696^2 + 31971^2 .

It is an emirp because it is prime and its reverse (752162022121) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-121220261257 is a prime.

It is not a weakly prime, because it can be changed into another prime (121220261207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60610130628 + 60610130629.

It is an arithmetic number, because the mean of its divisors is an integer number (60610130629).

Almost surely, 2^121220261257 is an apocalyptic number.

It is an amenable number.

121220261257 is a deficient number, since it is larger than the sum of its proper divisors (1).

121220261257 is an equidigital number, since it uses as much as digits as its factorization.

121220261257 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6720, while the sum is 31.

Adding to 121220261257 its reverse (752162022121), we get a palindrome (873382283378).

The spelling of 121220261257 in words is "one hundred twenty-one billion, two hundred twenty million, two hundred sixty-one thousand, two hundred fifty-seven".