121312521 has 24 divisors (see below), whose sum is σ = 192029760. Its totient is φ = 73188000.

The previous prime is 121312501. The next prime is 121312537. The reversal of 121312521 is 125213121.

121312521 is a `hidden beast` number, since 12 + 131 + 2 + 521 = 666.

It is not a de Polignac number, because 121312521 - 2¹³ = 121304329 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 121312494 and 121312503.

It is not an unprimeable number, because it can be changed into a prime (121312501) 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 in 23 ways as a sum of consecutive naturals, for example, 19996 + ... + 25346.

It is an arithmetic number, because the mean of its divisors is an integer number (8001240).

Almost surely, 2^121312521 is an apocalyptic number.

121312521 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

121312521 is a deficient number, since it is larger than the sum of its proper divisors (70717239).

121312521 is a wasteful number, since it uses less digits than its factorization.

121312521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5597 (or 5594 counting only the distinct ones).

The product of its digits is 120, while the sum is 18.

The square root of 121312521 is about 11014.1963392705. The cubic root of 121312521 is about 495.0342063904.

Adding to 121312521 its reverse (125213121), we get a palindrome (246525642).

The spelling of 121312521 in words is "one hundred twenty-one million, three hundred twelve thousand, five hundred twenty-one".