121335521 has 4 divisors (see below), whose sum is σ = 123044544. Its totient is φ = 119626500.

The previous prime is 121335493. The next prime is 121335541. The reversal of 121335521 is 125533121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 125533121 = 7 ⋅17933303.

It is a cyclic number.

It is not a de Polignac number, because 121335521 - 2¹⁴ = 121319137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121335541) 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 3 ways as a sum of consecutive naturals, for example, 854405 + ... + 854546.

It is an arithmetic number, because the mean of its divisors is an integer number (30761136).

Almost surely, 2^121335521 is an apocalyptic number.

It is an amenable number.

121335521 is a deficient number, since it is larger than the sum of its proper divisors (1709023).

121335521 is an equidigital number, since it uses as much as digits as its factorization.

121335521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1709022.

The product of its digits is 900, while the sum is 23.

The square root of 121335521 is about 11015.2403968320. The cubic root of 121335521 is about 495.0654894137.

Adding to 121335521 its reverse (125533121), we get a palindrome (246868642).

The spelling of 121335521 in words is "one hundred twenty-one million, three hundred thirty-five thousand, five hundred twenty-one".