40820909 has 2 divisors, whose sum is σ = 40820910. Its totient is φ = 40820908.

The previous prime is 40820891. The next prime is 40820921. The reversal of 40820909 is 90902804.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 25532809 + 15288100 = 5053^2 + 3910^2 .

It is a cyclic number.

It is not a de Polignac number, because 40820909 - 2¹⁶ = 40755373 is a prime.

It is a super-2 number, since 2×40820909² = 3332693223172562, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40820809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20410454 + 20410455.

It is an arithmetic number, because the mean of its divisors is an integer number (20410455).

Almost surely, 2^40820909 is an apocalyptic number.

It is an amenable number.

40820909 is a deficient number, since it is larger than the sum of its proper divisors (1).

40820909 is an equidigital number, since it uses as much as digits as its factorization.

40820909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 32.

The square root of 40820909 is about 6389.1242748909. The cubic root of 40820909 is about 344.3189223941.

The spelling of 40820909 in words is "forty million, eight hundred twenty thousand, nine hundred nine".