20645347 has 2 divisors, whose sum is σ = 20645348. Its totient is φ = 20645346.

The previous prime is 20645341. The next prime is 20645399. The reversal of 20645347 is 74354602.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20645347 is a prime.

It is not a weakly prime, because it can be changed into another prime (20645341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10322673 + 10322674.

It is an arithmetic number, because the mean of its divisors is an integer number (10322674).

Almost surely, 2^20645347 is an apocalyptic number.

20645347 is a deficient number, since it is larger than the sum of its proper divisors (1).

20645347 is an equidigital number, since it uses as much as digits as its factorization.

20645347 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 20160, while the sum is 31.

The square root of 20645347 is about 4543.7151099073. The cubic root of 20645347 is about 274.3304792828.

Adding to 20645347 its reverse (74354602), we get a palindrome (94999949).

The spelling of 20645347 in words is "twenty million, six hundred forty-five thousand, three hundred forty-seven".