20063891 has 4 divisors (see below), whose sum is σ = 20251512. Its totient is φ = 19876272.

The previous prime is 20063809. The next prime is 20063899. The reversal of 20063891 is 19836002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20063891 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20063899) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 93650 + ... + 93863.

It is an arithmetic number, because the mean of its divisors is an integer number (5062878).

Almost surely, 2^20063891 is an apocalyptic number.

20063891 is a deficient number, since it is larger than the sum of its proper divisors (187621).

20063891 is a wasteful number, since it uses less digits than its factorization.

20063891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 187620.

The product of its (nonzero) digits is 2592, while the sum is 29.

The square root of 20063891 is about 4479.2734901991. The cubic root of 20063891 is about 271.7304991752.

Adding to 20063891 its reverse (19836002), we get a palindrome (39899893).

The spelling of 20063891 in words is "twenty million, sixty-three thousand, eight hundred ninety-one".