11821501 has 2 divisors, whose sum is σ = 11821502. Its totient is φ = 11821500.

The previous prime is 11821499. The next prime is 11821507. The reversal of 11821501 is 10512811.

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., 7284601 + 4536900 = 2699^2 + 2130^2 .

It is an emirp because it is prime and its reverse (10512811) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11821501 - 2¹ = 11821499 is a prime.

Together with 11821499, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (11821507) 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 as a sum of consecutive naturals, namely, 5910750 + 5910751.

It is an arithmetic number, because the mean of its divisors is an integer number (5910751).

Almost surely, 2^11821501 is an apocalyptic number.

It is an amenable number.

11821501 is a deficient number, since it is larger than the sum of its proper divisors (1).

11821501 is an equidigital number, since it uses as much as digits as its factorization.

11821501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 80, while the sum is 19.

The square root of 11821501 is about 3438.2409746846. The cubic root of 11821501 is about 227.8020044207.

The spelling of 11821501 in words is "eleven million, eight hundred twenty-one thousand, five hundred one".