40638813 has 4 divisors (see below), whose sum is σ = 54185088. Its totient is φ = 27092540.

The previous prime is 40638803. The next prime is 40638817. The reversal of 40638813 is 31883604.

40638813 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 40638813 - 2¹³ = 40630621 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40638817) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6773133 + ... + 6773138.

It is an arithmetic number, because the mean of its divisors is an integer number (13546272).

Almost surely, 2^40638813 is an apocalyptic number.

It is an amenable number.

40638813 is a deficient number, since it is larger than the sum of its proper divisors (13546275).

40638813 is a wasteful number, since it uses less digits than its factorization.

40638813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13546274.

The product of its (nonzero) digits is 13824, while the sum is 33.

The square root of 40638813 is about 6374.8578807688. The cubic root of 40638813 is about 343.8061740484.

The spelling of 40638813 in words is "forty million, six hundred thirty-eight thousand, eight hundred thirteen".