20128447 has 2 divisors, whose sum is σ = 20128448. Its totient is φ = 20128446.

The previous prime is 20128439. The next prime is 20128453. The reversal of 20128447 is 74482102.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20128447 - 2³ = 20128439 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20128477) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10064223 + 10064224.

It is an arithmetic number, because the mean of its divisors is an integer number (10064224).

Almost surely, 2^20128447 is an apocalyptic number.

20128447 is a deficient number, since it is larger than the sum of its proper divisors (1).

20128447 is an equidigital number, since it uses as much as digits as its factorization.

20128447 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3584, while the sum is 28.

The square root of 20128447 is about 4486.4737823819. The cubic root of 20128447 is about 272.0216200736.

The spelling of 20128447 in words is "twenty million, one hundred twenty-eight thousand, four hundred forty-seven".