40780009 has 2 divisors, whose sum is σ = 40780010. Its totient is φ = 40780008.

The previous prime is 40780007. The next prime is 40780049. The reversal of 40780009 is 90008704.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 26491609 + 14288400 = 5147^2 + 3780^2 .

It is a cyclic number.

It is not a de Polignac number, because 40780009 - 2¹ = 40780007 is a prime.

Together with 40780007, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (40780001) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20390004 + 20390005.

It is an arithmetic number, because the mean of its divisors is an integer number (20390005).

Almost surely, 2^40780009 is an apocalyptic number.

It is an amenable number.

40780009 is a deficient number, since it is larger than the sum of its proper divisors (1).

40780009 is an equidigital number, since it uses as much as digits as its factorization.

40780009 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 28.

The square root of 40780009 is about 6385.9227211109. The cubic root of 40780009 is about 344.2038886186.

The spelling of 40780009 in words is "forty million, seven hundred eighty thousand, nine".