40520639837 has 4 divisors (see below), whose sum is σ = 40533932700. Its totient is φ = 40507346976.

The previous prime is 40520639773. The next prime is 40520639857. The reversal of 40520639837 is 73893602504.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16695482521 + 23825157316 = 129211^2 + 154354^2 .

It is a cyclic number.

It is not a de Polignac number, because 40520639837 - 2⁶ = 40520639773 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 40520639791 and 40520639800.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40520639857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6641858 + ... + 6647955.

It is an arithmetic number, because the mean of its divisors is an integer number (10133483175).

Almost surely, 2^40520639837 is an apocalyptic number.

It is an amenable number.

40520639837 is a deficient number, since it is larger than the sum of its proper divisors (13292863).

40520639837 is a wasteful number, since it uses less digits than its factorization.

40520639837 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13292862.

The product of its (nonzero) digits is 1088640, while the sum is 47.

The spelling of 40520639837 in words is "forty billion, five hundred twenty million, six hundred thirty-nine thousand, eight hundred thirty-seven".