20273206781 has 2 divisors, whose sum is σ = 20273206782. Its totient is φ = 20273206780.

The previous prime is 20273206771. The next prime is 20273206783. The reversal of 20273206781 is 18760237202.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17611678681 + 2661528100 = 132709^2 + 51590^2 .

It is a cyclic number.

It is not a de Polignac number, because 20273206781 - 2¹⁴ = 20273190397 is a prime.

It is a super-2 number, since 2×20273206781² (a number of 21 digits) contains 22 as substring.

Together with 20273206783, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20273206783) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10136603390 + 10136603391.

It is an arithmetic number, because the mean of its divisors is an integer number (10136603391).

Almost surely, 2^20273206781 is an apocalyptic number.

It is an amenable number.

20273206781 is a deficient number, since it is larger than the sum of its proper divisors (1).

20273206781 is an equidigital number, since it uses as much as digits as its factorization.

20273206781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 56448, while the sum is 38.

The spelling of 20273206781 in words is "twenty billion, two hundred seventy-three million, two hundred six thousand, seven hundred eighty-one".