20660851 has 2 divisors, whose sum is σ = 20660852. Its totient is φ = 20660850.

The previous prime is 20660839. The next prime is 20660869. The reversal of 20660851 is 15806602.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20660851 - 2¹³ = 20652659 is a prime.

It is not a weakly prime, because it can be changed into another prime (20660881) 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, 10330425 + 10330426.

It is an arithmetic number, because the mean of its divisors is an integer number (10330426).

Almost surely, 2^20660851 is an apocalyptic number.

20660851 is a deficient number, since it is larger than the sum of its proper divisors (1).

20660851 is an equidigital number, since it uses as much as digits as its factorization.

20660851 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 20660851 is about 4545.4208826026. The cubic root of 20660851 is about 274.3991332595.

The spelling of 20660851 in words is "twenty million, six hundred sixty thousand, eight hundred fifty-one".