11531987 has 2 divisors, whose sum is σ = 11531988. Its totient is φ = 11531986.

The previous prime is 11531977. The next prime is 11532011. The reversal of 11531987 is 78913511.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 11531987 - 2⁸ = 11531731 is a prime.

It is not a weakly prime, because it can be changed into another prime (11531977) 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 as a sum of consecutive naturals, namely, 5765993 + 5765994.

It is an arithmetic number, because the mean of its divisors is an integer number (5765994).

Almost surely, 2^11531987 is an apocalyptic number.

11531987 is a deficient number, since it is larger than the sum of its proper divisors (1).

11531987 is an equidigital number, since it uses as much as digits as its factorization.

11531987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7560, while the sum is 35.

The square root of 11531987 is about 3395.8779424473. The cubic root of 11531987 is about 225.9269544915.

The spelling of 11531987 in words is "eleven million, five hundred thirty-one thousand, nine hundred eighty-seven".