40384519681 has 9 divisors (see below), whose sum is σ = 44392025923. Its totient is φ = 36711190120.

The previous prime is 40384519667. The next prime is 40384519687. The reversal of 40384519681 is 18691548304.

It is a happy number.

The square root of 40384519681 is 200959.

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

It can be written as a sum of positive squares in only one way, i.e., 29186647281 + 11197872400 = 170841^2 + 105820^2 .

It is not a de Polignac number, because 40384519681 - 2⁵ = 40384519649 is a prime.

It is a super-2 number, since 2×40384519681² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40384519687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 2201415 + ... + 2219683.

Almost surely, 2^40384519681 is an apocalyptic number.

40384519681 is the 200959-th square number.

40384519681 is the 100480-th centered octagonal number.

It is an amenable number.

40384519681 is a deficient number, since it is larger than the sum of its proper divisors (4007506242).

40384519681 is an frugal number, since it uses more digits than its factorization.

40384519681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36560 (or 18280 counting only the distinct ones).

The product of its (nonzero) digits is 829440, while the sum is 49.

Multiplying 40384519681 by its sum of digits (49), we get a square (1978841464369 = 1406713²).

It can be divided in two parts, 40384 and 519681, that added together give a palindrome (560065).

The spelling of 40384519681 in words is "forty billion, three hundred eighty-four million, five hundred nineteen thousand, six hundred eighty-one".