1638814746244 has 81 divisors (see below), whose sum is σ = 3168616234413. Its totient is φ = 741305969664.

The previous prime is 1638814746241. The next prime is 1638814746263. The reversal of 1638814746244 is 4426474188361.

The square root of 1638814746244 is 1280162.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 13 ways, for example, as 1637985306244 + 829440000 = 1279838^2 + 28800^2 .

It is a super-2 number, since 2×1638814746244² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1638814746241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 1764062772 + ... + 1764063700.

Almost surely, 2^{1638814746244} is an apocalyptic number.

1638814746244 is the 1280162-nd square number.

It is an amenable number.

1638814746244 is a deficient number, since it is larger than the sum of its proper divisors (1529801488169).

1638814746244 is an frugal number, since it uses more digits than its factorization.

1638814746244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1994 (or 997 counting only the distinct ones).

The product of its digits is 24772608, while the sum is 58.

The spelling of 1638814746244 in words is "one trillion, six hundred thirty-eight billion, eight hundred fourteen million, seven hundred forty-six thousand, two hundred forty-four".