491161644 has 120 divisors (see below), whose sum is σ = 1344358400. Its totient is φ = 156180960.

The previous prime is 491161633. The next prime is 491161667. The reversal of 491161644 is 446161194.

491161644 is a `hidden beast` number, since 4 + 9 + 1 + 1 + 6 + 1 + 644 = 666.

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

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 491161599 and 491161608.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 793167 + ... + 793785.

Almost surely, 2^491161644 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 491161644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (672179200).

491161644 is an abundant number, since it is smaller than the sum of its proper divisors (853196756).

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

491161644 is a wasteful number, since it uses less digits than its factorization.

491161644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 745 (or 734 counting only the distinct ones).

The product of its digits is 20736, while the sum is 36.

The square root of 491161644 is about 22162.1669518123. The cubic root of 491161644 is about 788.9960242105.

The spelling of 491161644 in words is "four hundred ninety-one million, one hundred sixty-one thousand, six hundred forty-four".