20076781 has 2 divisors, whose sum is σ = 20076782. Its totient is φ = 20076780.

The previous prime is 20076773. The next prime is 20076799. The reversal of 20076781 is 18767002.

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., 18412681 + 1664100 = 4291^2 + 1290^2 .

It is a cyclic number.

It is not a de Polignac number, because 20076781 - 2³ = 20076773 is a prime.

It is a super-2 number, since 2×20076781² = 806154270643922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20076181) 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, 10038390 + 10038391.

It is an arithmetic number, because the mean of its divisors is an integer number (10038391).

Almost surely, 2^20076781 is an apocalyptic number.

It is an amenable number.

20076781 is a deficient number, since it is larger than the sum of its proper divisors (1).

20076781 is an equidigital number, since it uses as much as digits as its factorization.

20076781 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 20076781 is about 4480.7121085827. The cubic root of 20076781 is about 271.7886775933.

The spelling of 20076781 in words is "twenty million, seventy-six thousand, seven hundred eighty-one".