121331553 has 16 divisors (see below), whose sum is σ = 188021760. Its totient is φ = 68156496.

The previous prime is 121331531. The next prime is 121331627. The reversal of 121331553 is 355133121.

It is not a de Polignac number, because 121331553 - 2¹⁰ = 121330529 is a prime.

It is not an unprimeable number, because it can be changed into a prime (121331513) 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 in 15 ways as a sum of consecutive naturals, for example, 47725 + ... + 50202.

It is an arithmetic number, because the mean of its divisors is an integer number (11751360).

Almost surely, 2^121331553 is an apocalyptic number.

It is an amenable number.

121331553 is a deficient number, since it is larger than the sum of its proper divisors (66690207).

121331553 is an equidigital number, since it uses as much as digits as its factorization.

121331553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 97996.

The product of its digits is 1350, while the sum is 24.

The square root of 121331553 is about 11015.0602812695. The cubic root of 121331553 is about 495.0600926943.

Adding to 121331553 its reverse (355133121), we get a palindrome (476464674).

The spelling of 121331553 in words is "one hundred twenty-one million, three hundred thirty-one thousand, five hundred fifty-three".