121431553 has 2 divisors, whose sum is σ = 121431554. Its totient is φ = 121431552.

The previous prime is 121431551. The next prime is 121431587. The reversal of 121431553 is 355134121.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 120494529 + 937024 = 10977^2 + 968^2 .

It is an emirp because it is prime and its reverse (355134121) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 121431553 - 2¹ = 121431551 is a prime.

Together with 121431551, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (121431551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 60715776 + 60715777.

It is an arithmetic number, because the mean of its divisors is an integer number (60715777).

Almost surely, 2^121431553 is an apocalyptic number.

It is an amenable number.

121431553 is a deficient number, since it is larger than the sum of its proper divisors (1).

121431553 is an equidigital number, since it uses as much as digits as its factorization.

121431553 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1800, while the sum is 25.

The square root of 121431553 is about 11019.5985861555. The cubic root of 121431553 is about 495.1960628618.

Adding to 121431553 its reverse (355134121), we get a palindrome (476565674).

The spelling of 121431553 in words is "one hundred twenty-one million, four hundred thirty-one thousand, five hundred fifty-three".