40243209 has 4 divisors (see below), whose sum is σ = 53657616. Its totient is φ = 26828804.

The previous prime is 40243201. The next prime is 40243211. The reversal of 40243209 is 90234204.

It is a happy number.

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 40243209 - 2³ = 40243201 is a prime.

It is not an unprimeable number, because it can be changed into a prime (40243201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6707199 + ... + 6707204.

It is an arithmetic number, because the mean of its divisors is an integer number (13414404).

Almost surely, 2^40243209 is an apocalyptic number.

It is an amenable number.

40243209 is a deficient number, since it is larger than the sum of its proper divisors (13414407).

40243209 is a wasteful number, since it uses less digits than its factorization.

40243209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13414406.

The product of its (nonzero) digits is 1728, while the sum is 24.

The square root of 40243209 is about 6343.7535418709. The cubic root of 40243209 is about 342.6869251541.

The spelling of 40243209 in words is "forty million, two hundred forty-three thousand, two hundred nine".