20138851 has 2 divisors, whose sum is σ = 20138852. Its totient is φ = 20138850.

The previous prime is 20138843. The next prime is 20138903. The reversal of 20138851 is 15883102.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20138851 - 2³ = 20138843 is a prime.

It is not a weakly prime, because it can be changed into another prime (20138801) 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, 10069425 + 10069426.

It is an arithmetic number, because the mean of its divisors is an integer number (10069426).

Almost surely, 2^20138851 is an apocalyptic number.

20138851 is a deficient number, since it is larger than the sum of its proper divisors (1).

20138851 is an equidigital number, since it uses as much as digits as its factorization.

20138851 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 20138851 is about 4487.6331178027. The cubic root of 20138851 is about 272.0684795500.

The spelling of 20138851 in words is "twenty million, one hundred thirty-eight thousand, eight hundred fifty-one".