40856639 has 2 divisors, whose sum is σ = 40856640. Its totient is φ = 40856638.

The previous prime is 40856633. The next prime is 40856657. The reversal of 40856639 is 93665804.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 40856639 - 2²⁰ = 39808063 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 40856596 and 40856605.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40856633) 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 as a sum of consecutive naturals, namely, 20428319 + 20428320.

It is an arithmetic number, because the mean of its divisors is an integer number (20428320).

Almost surely, 2^40856639 is an apocalyptic number.

40856639 is a deficient number, since it is larger than the sum of its proper divisors (1).

40856639 is an equidigital number, since it uses as much as digits as its factorization.

40856639 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 155520, while the sum is 41.

The square root of 40856639 is about 6391.9198211492. The cubic root of 40856639 is about 344.4193523595.

The spelling of 40856639 in words is "forty million, eight hundred fifty-six thousand, six hundred thirty-nine".