11993561 has 2 divisors, whose sum is σ = 11993562. Its totient is φ = 11993560.

The previous prime is 11993549. The next prime is 11993563. The reversal of 11993561 is 16539911.

11993561 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 9803161 + 2190400 = 3131^2 + 1480^2 .

It is a cyclic number.

It is not a de Polignac number, because 11993561 - 2²² = 7799257 is a prime.

Together with 11993563, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (11993563) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5996780 + 5996781.

It is an arithmetic number, because the mean of its divisors is an integer number (5996781).

Almost surely, 2^11993561 is an apocalyptic number.

It is an amenable number.

11993561 is a deficient number, since it is larger than the sum of its proper divisors (1).

11993561 is an equidigital number, since it uses as much as digits as its factorization.

11993561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7290, while the sum is 35.

The square root of 11993561 is about 3463.1721008347. The cubic root of 11993561 is about 228.9018922120.

The spelling of 11993561 in words is "eleven million, nine hundred ninety-three thousand, five hundred sixty-one".