11993521 has 2 divisors, whose sum is σ = 11993522. Its totient is φ = 11993520.

The previous prime is 11993519. The next prime is 11993539. The reversal of 11993521 is 12539911.

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., 11289600 + 703921 = 3360^2 + 839^2 .

It is a cyclic number.

It is not a de Polignac number, because 11993521 - 2¹ = 11993519 is a prime.

Together with 11993519, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (11993561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5996760 + 5996761.

It is an arithmetic number, because the mean of its divisors is an integer number (5996761).

Almost surely, 2^11993521 is an apocalyptic number.

It is an amenable number.

11993521 is a deficient number, since it is larger than the sum of its proper divisors (1).

11993521 is an equidigital number, since it uses as much as digits as its factorization.

11993521 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2430, while the sum is 31.

The square root of 11993521 is about 3463.1663257776. The cubic root of 11993521 is about 228.9016377398.

The spelling of 11993521 in words is "eleven million, nine hundred ninety-three thousand, five hundred twenty-one".