40740209 has 2 divisors, whose sum is σ = 40740210. Its totient is φ = 40740208.

The previous prime is 40740197. The next prime is 40740233. The reversal of 40740209 is 90204704.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23309584 + 17430625 = 4828^2 + 4175^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40740209 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a zygodrome in base 3.

It is not a weakly prime, because it can be changed into another prime (40740509) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20370104 + 20370105.

It is an arithmetic number, because the mean of its divisors is an integer number (20370105).

Almost surely, 2^40740209 is an apocalyptic number.

It is an amenable number.

40740209 is a deficient number, since it is larger than the sum of its proper divisors (1).

40740209 is an equidigital number, since it uses as much as digits as its factorization.

40740209 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 40740209 is about 6382.8057310246. The cubic root of 40740209 is about 344.0918747976.

The spelling of 40740209 in words is "forty million, seven hundred forty thousand, two hundred nine".