20770861 has 2 divisors, whose sum is σ = 20770862. Its totient is φ = 20770860.

The previous prime is 20770847. The next prime is 20770903. The reversal of 20770861 is 16807702.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12180100 + 8590761 = 3490^2 + 2931^2 .

It is a cyclic number.

It is not a de Polignac number, because 20770861 - 2⁹ = 20770349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20770831) 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, 10385430 + 10385431.

It is an arithmetic number, because the mean of its divisors is an integer number (10385431).

Almost surely, 2^20770861 is an apocalyptic number.

It is an amenable number.

20770861 is a deficient number, since it is larger than the sum of its proper divisors (1).

20770861 is an equidigital number, since it uses as much as digits as its factorization.

20770861 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4704, while the sum is 31.

The square root of 20770861 is about 4557.5060065786. The cubic root of 20770861 is about 274.8852898989.

The spelling of 20770861 in words is "twenty million, seven hundred seventy thousand, eight hundred sixty-one".