639641041 has 8 divisors (see below), whose sum is σ = 705645864. Its totient is φ = 576036480.

The previous prime is 639641033. The next prime is 639641087. The reversal of 639641041 is 140146936.

It can be written as a sum of positive squares in 4 ways, for example, as 55935441 + 583705600 = 7479^2 + 24160^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 639641041 - 2³ = 639641033 is a prime.

It is a super-2 number, since 2×639641041² = 818281322663127362, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 639640988 and 639641006.

It is not an unprimeable number, because it can be changed into a prime (639681041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 599506 + ... + 600571.

It is an arithmetic number, because the mean of its divisors is an integer number (88205733).

Almost surely, 2^639641041 is an apocalyptic number.

It is an amenable number.

639641041 is a deficient number, since it is larger than the sum of its proper divisors (66004823).

639641041 is a wasteful number, since it uses less digits than its factorization.

639641041 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1200131.

The product of its (nonzero) digits is 15552, while the sum is 34.

The square root of 639641041 is about 25291.1257361154. The cubic root of 639641041 is about 861.6127305229.

Adding to 639641041 its reverse (140146936), we get a palindrome (779787977).

The spelling of 639641041 in words is "six hundred thirty-nine million, six hundred forty-one thousand, forty-one".