20145847 has 2 divisors, whose sum is σ = 20145848. Its totient is φ = 20145846.

The previous prime is 20145821. The next prime is 20145857. The reversal of 20145847 is 74854102.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20145847 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20145857) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10072923 + 10072924.

It is an arithmetic number, because the mean of its divisors is an integer number (10072924).

Almost surely, 2^20145847 is an apocalyptic number.

20145847 is a deficient number, since it is larger than the sum of its proper divisors (1).

20145847 is an equidigital number, since it uses as much as digits as its factorization.

20145847 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8960, while the sum is 31.

The square root of 20145847 is about 4488.4125256041. The cubic root of 20145847 is about 272.0999803660.

Adding to 20145847 its reverse (74854102), we get a palindrome (94999949).

The spelling of 20145847 in words is "twenty million, one hundred forty-five thousand, eight hundred forty-seven".