40561909 has 2 divisors, whose sum is σ = 40561910. Its totient is φ = 40561908.

The previous prime is 40561897. The next prime is 40561921. The reversal of 40561909 is 90916504.

It is a balanced prime because it is at equal distance from previous prime (40561897) and next prime (40561921).

It can be written as a sum of positive squares in only one way, i.e., 23571025 + 16990884 = 4855^2 + 4122^2 .

It is a cyclic number.

It is not a de Polignac number, because 40561909 - 2⁵ = 40561877 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40561999) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20280954 + 20280955.

It is an arithmetic number, because the mean of its divisors is an integer number (20280955).

Almost surely, 2^40561909 is an apocalyptic number.

It is an amenable number.

40561909 is a deficient number, since it is larger than the sum of its proper divisors (1).

40561909 is an equidigital number, since it uses as much as digits as its factorization.

40561909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9720, while the sum is 34.

The square root of 40561909 is about 6368.8232037010. The cubic root of 40561909 is about 343.5891666786.

The spelling of 40561909 in words is "forty million, five hundred sixty-one thousand, nine hundred nine".