8491644 has 72 divisors (see below), whose sum is σ = 25346048. Its totient is φ = 2345760.

The previous prime is 8491643. The next prime is 8491663. The reversal of 8491644 is 4461948.

It is a happy number.

8491644 is a `hidden beast` number, since 8 + 4 + 9 + 1 + 644 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 8491599 and 8491608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8491643) 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, 7269 + ... + 8355.

Almost surely, 2^8491644 is an apocalyptic number.

8491644 is a gapful number since it is divisible by the number (84) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 8491644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (12673024).

8491644 is an abundant number, since it is smaller than the sum of its proper divisors (16854404).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

8491644 is a wasteful number, since it uses less digits than its factorization.

8491644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1135 (or 1130 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The square root of 8491644 is about 2914.0425528808. The cubic root of 8491644 is about 204.0158580521.

The spelling of 8491644 in words is "eight million, four hundred ninety-one thousand, six hundred forty-four".