121000559821 has 2 divisors, whose sum is σ = 121000559822. Its totient is φ = 121000559820.

The previous prime is 121000559791. The next prime is 121000559831. The reversal of 121000559821 is 128955000121.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 91014442596 + 29986117225 = 301686^2 + 173165^2 .

It is an emirp because it is prime and its reverse (128955000121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121000559821 - 2¹⁷ = 121000428749 is a prime.

It is a super-2 number, since 2×121000559821² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (121000559831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60500279910 + 60500279911.

It is an arithmetic number, because the mean of its divisors is an integer number (60500279911).

Almost surely, 2^121000559821 is an apocalyptic number.

It is an amenable number.

121000559821 is a deficient number, since it is larger than the sum of its proper divisors (1).

121000559821 is an equidigital number, since it uses as much as digits as its factorization.

121000559821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7200, while the sum is 34.

Adding to 121000559821 its reverse (128955000121), we get a palindrome (249955559942).

The spelling of 121000559821 in words is "one hundred twenty-one billion, five hundred fifty-nine thousand, eight hundred twenty-one".