20416309 has 2 divisors, whose sum is σ = 20416310. Its totient is φ = 20416308.

The previous prime is 20416247. The next prime is 20416313. The reversal of 20416309 is 90361402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14799409 + 5616900 = 3847^2 + 2370^2 .

It is a cyclic number.

It is not a de Polignac number, because 20416309 - 2¹³ = 20408117 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20416339) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10208154 + 10208155.

It is an arithmetic number, because the mean of its divisors is an integer number (10208155).

Almost surely, 2^20416309 is an apocalyptic number.

It is an amenable number.

20416309 is a deficient number, since it is larger than the sum of its proper divisors (1).

20416309 is an equidigital number, since it uses as much as digits as its factorization.

20416309 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 20416309 is about 4518.4409922007. The cubic root of 20416309 is about 273.3122369533.

The spelling of 20416309 in words is "twenty million, four hundred sixteen thousand, three hundred nine".