11899861 has 2 divisors, whose sum is σ = 11899862. Its totient is φ = 11899860.

The previous prime is 11899859. The next prime is 11899879. The reversal of 11899861 is 16899811.

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., 10929636 + 970225 = 3306^2 + 985^2 .

It is an emirp because it is prime and its reverse (16899811) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 11899861 - 2¹ = 11899859 is a prime.

Together with 11899859, 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 (11899841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5949930 + 5949931.

It is an arithmetic number, because the mean of its divisors is an integer number (5949931).

Almost surely, 2^11899861 is an apocalyptic number.

It is an amenable number.

11899861 is a deficient number, since it is larger than the sum of its proper divisors (1).

11899861 is an equidigital number, since it uses as much as digits as its factorization.

11899861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 43.

The square root of 11899861 is about 3449.6175150297. The cubic root of 11899861 is about 228.3042324727.

The spelling of 11899861 in words is "eleven million, eight hundred ninety-nine thousand, eight hundred sixty-one".