40206643 has 4 divisors (see below), whose sum is σ = 40562568. Its totient is φ = 39850720.

The previous prime is 40206637. The next prime is 40206653. The reversal of 40206643 is 34660204.

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

It is a cyclic number.

It is not a de Polignac number, because 40206643 - 2²⁵ = 6652211 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (40206613) 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 3 ways as a sum of consecutive naturals, for example, 177793 + ... + 178018.

It is an arithmetic number, because the mean of its divisors is an integer number (10140642).

Almost surely, 2^40206643 is an apocalyptic number.

40206643 is a deficient number, since it is larger than the sum of its proper divisors (355925).

40206643 is a wasteful number, since it uses less digits than its factorization.

40206643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 355924.

The product of its (nonzero) digits is 3456, while the sum is 25.

The square root of 40206643 is about 6340.8708392460. The cubic root of 40206643 is about 342.5831023596.

Adding to 40206643 its reverse (34660204), we get a palindrome (74866847).

The spelling of 40206643 in words is "forty million, two hundred six thousand, six hundred forty-three".