121306513 has 4 divisors (see below), whose sum is σ = 122192100. Its totient is φ = 120420928.

The previous prime is 121306487. The next prime is 121306561. The reversal of 121306513 is 315603121.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 315603121 = 1187 ⋅265883.

It can be written as a sum of positive squares in 2 ways, for example, as 103388224 + 17918289 = 10168^2 + 4233^2 .

It is a cyclic number.

It is not a de Polignac number, because 121306513 - 2¹⁷ = 121175441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (121306573) 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, 442588 + ... + 442861.

It is an arithmetic number, because the mean of its divisors is an integer number (30548025).

Almost surely, 2^121306513 is an apocalyptic number.

It is an amenable number.

121306513 is a deficient number, since it is larger than the sum of its proper divisors (885587).

121306513 is an equidigital number, since it uses as much as digits as its factorization.

121306513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 885586.

The product of its (nonzero) digits is 540, while the sum is 22.

The square root of 121306513 is about 11013.9235969749. The cubic root of 121306513 is about 495.0260340693.

Adding to 121306513 its reverse (315603121), we get a palindrome (436909634).

It can be divided in two parts, 121 and 306513, that multiplied together give a palindrome (37088073).

The spelling of 121306513 in words is "one hundred twenty-one million, three hundred six thousand, five hundred thirteen".