20395891 has 2 divisors, whose sum is σ = 20395892. Its totient is φ = 20395890.

The previous prime is 20395883. The next prime is 20395897. The reversal of 20395891 is 19859302.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20395891 - 2³ = 20395883 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20395891.

It is not a weakly prime, because it can be changed into another prime (20395897) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10197945 + 10197946.

It is an arithmetic number, because the mean of its divisors is an integer number (10197946).

Almost surely, 2^20395891 is an apocalyptic number.

20395891 is a deficient number, since it is larger than the sum of its proper divisors (1).

20395891 is an equidigital number, since it uses as much as digits as its factorization.

20395891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 19440, while the sum is 37.

The square root of 20395891 is about 4516.1810194012. The cubic root of 20395891 is about 273.2210949386.

The spelling of 20395891 in words is "twenty million, three hundred ninety-five thousand, eight hundred ninety-one".