663491736 has 80 divisors (see below), whose sum is σ = 1893553200. Its totient is φ = 216979776.

The previous prime is 663491711. The next prime is 663491749. The reversal of 663491736 is 637194366.

663491736 is a `hidden beast` number, since 6 + 634 + 9 + 1 + 7 + 3 + 6 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 663491691 and 663491700.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 24685 + ... + 44003.

It is an arithmetic number, because the mean of its divisors is an integer number (23669415).

Almost surely, 2^663491736 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 663491736, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (946776600).

663491736 is an abundant number, since it is smaller than the sum of its proper divisors (1230061464).

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

663491736 is a wasteful number, since it uses less digits than its factorization.

663491736 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19390 (or 19377 counting only the distinct ones).

The product of its digits is 489888, while the sum is 45.

The square root of 663491736 is about 25758.3333311765. Note that the first 5 decimals coincide. The cubic root of 663491736 is about 872.1914787264.

The spelling of 663491736 in words is "six hundred sixty-three million, four hundred ninety-one thousand, seven hundred thirty-six".