9917861 has 4 divisors (see below), whose sum is σ = 10237824. Its totient is φ = 9597900.

The previous prime is 9917849. The next prime is 9917881. The reversal of 9917861 is 1687199.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 9917861 - 2¹⁸ = 9655717 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9917881) 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 in 3 ways as a sum of consecutive naturals, for example, 159935 + ... + 159996.

It is an arithmetic number, because the mean of its divisors is an integer number (2559456).

Almost surely, 2^9917861 is an apocalyptic number.

It is an amenable number.

9917861 is a deficient number, since it is larger than the sum of its proper divisors (319963).

9917861 is a wasteful number, since it uses less digits than its factorization.

9917861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 319962.

The product of its digits is 27216, while the sum is 41.

The square root of 9917861 is about 3149.2635647084. The cubic root of 9917861 is about 214.8519694923.

The spelling of 9917861 in words is "nine million, nine hundred seventeen thousand, eight hundred sixty-one".