20645311 has 2 divisors, whose sum is σ = 20645312. Its totient is φ = 20645310.

The previous prime is 20645281. The next prime is 20645321. The reversal of 20645311 is 11354602.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20645311 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20645321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10322655 + 10322656.

It is an arithmetic number, because the mean of its divisors is an integer number (10322656).

Almost surely, 2^20645311 is an apocalyptic number.

20645311 is a deficient number, since it is larger than the sum of its proper divisors (1).

20645311 is an equidigital number, since it uses as much as digits as its factorization.

20645311 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 20645311 is about 4543.7111483896. The cubic root of 20645311 is about 274.3303198295.

Adding to 20645311 its reverse (11354602), we get a palindrome (31999913).

The spelling of 20645311 in words is "twenty million, six hundred forty-five thousand, three hundred eleven".