1663842726 has 216 divisors, whose sum is σ = 4697430192. Its totient is φ = 421848000.

The previous prime is 1663842721. The next prime is 1663842767. The reversal of 1663842726 is 6272483661.

1663842726 is a `hidden beast` number, since 1 + 6 + 638 + 4 + 2 + 7 + 2 + 6 = 666.

It is a super-2 number, since 2×1663842726² = 5536745233726222152, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663842721) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 11018751 + ... + 11018901.

It is an arithmetic number, because the mean of its divisors is an integer number (21747362).

Almost surely, 2^1663842726 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1663842726, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2348715096).

1663842726 is an abundant number, since it is smaller than the sum of its proper divisors (3033587466).

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

1663842726 is a wasteful number, since it uses less digits than its factorization.

1663842726 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 248 (or 207 counting only the distinct ones).

The product of its digits is 580608, while the sum is 45.

The square root of 1663842726 is about 40790.2283151247. The cubic root of 1663842726 is about 1184.9610925644.

The spelling of 1663842726 in words is "one billion, six hundred sixty-three million, eight hundred forty-two thousand, seven hundred twenty-six".