9911861 has 2 divisors, whose sum is σ = 9911862. Its totient is φ = 9911860.

The previous prime is 9911857. The next prime is 9911917. The reversal of 9911861 is 1681199.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 5202961 + 4708900 = 2281^2 + 2170^2 .

It is a cyclic number.

It is not a de Polignac number, because 9911861 - 2² = 9911857 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (9911821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 4955930 + 4955931.

It is an arithmetic number, because the mean of its divisors is an integer number (4955931).

Almost surely, 2^9911861 is an apocalyptic number.

It is an amenable number.

9911861 is a deficient number, since it is larger than the sum of its proper divisors (1).

9911861 is an equidigital number, since it uses as much as digits as its factorization.

9911861 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3888, while the sum is 35.

The square root of 9911861 is about 3148.3108169302. The cubic root of 9911861 is about 214.8086344807.

The spelling of 9911861 in words is "nine million, nine hundred eleven thousand, eight hundred sixty-one".