9861566 has 48 divisors (see below), whose sum is σ = 18437328. Its totient is φ = 3897600.

The previous prime is 9861563. The next prime is 9861569. The reversal of 9861566 is 6651689.

It is an interprime number because it is at equal distance from previous prime (9861563) and next prime (9861569).

It is a Harshad number since it is a multiple of its sum of digits (41).

Its product of digits (77760) is a multiple of the sum of its prime divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9861563) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 240506 + ... + 240546.

It is an arithmetic number, because the mean of its divisors is an integer number (384111).

Almost surely, 2^9861566 is an apocalyptic number.

9861566 is a deficient number, since it is larger than the sum of its proper divisors (8575762).

9861566 is a wasteful number, since it uses less digits than its factorization.

9861566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125 (or 96 counting only the distinct ones).

The product of its digits is 77760, while the sum is 41.

The square root of 9861566 is about 3140.3130417205. The cubic root of 9861566 is about 214.4446891835. Note that the first 3 decimals are identical.

It can be divided in two parts, 986 and 1566, that added together give a palindrome (2552).

The spelling of 9861566 in words is "nine million, eight hundred sixty-one thousand, five hundred sixty-six".