20765851 has 2 divisors, whose sum is σ = 20765852. Its totient is φ = 20765850.

The previous prime is 20765837. The next prime is 20765873. The reversal of 20765851 is 15856702.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20765851 - 2¹⁹ = 20241563 is a prime.

It is not a weakly prime, because it can be changed into another prime (20765831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10382925 + 10382926.

It is an arithmetic number, because the mean of its divisors is an integer number (10382926).

Almost surely, 2^20765851 is an apocalyptic number.

20765851 is a deficient number, since it is larger than the sum of its proper divisors (1).

20765851 is an equidigital number, since it uses as much as digits as its factorization.

20765851 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 16800, while the sum is 34.

The square root of 20765851 is about 4556.9563307102. The cubic root of 20765851 is about 274.8631870430.

The spelling of 20765851 in words is "twenty million, seven hundred sixty-five thousand, eight hundred fifty-one".