20720893 has 2 divisors, whose sum is σ = 20720894. Its totient is φ = 20720892.

The previous prime is 20720789. The next prime is 20720899. The reversal of 20720893 is 39802702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 20593444 + 127449 = 4538^2 + 357^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20720893 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20720899) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10360446 + 10360447.

It is an arithmetic number, because the mean of its divisors is an integer number (10360447).

Almost surely, 2^20720893 is an apocalyptic number.

It is an amenable number.

20720893 is a deficient number, since it is larger than the sum of its proper divisors (1).

20720893 is an equidigital number, since it uses as much as digits as its factorization.

20720893 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 20720893 is about 4552.0207600581. The cubic root of 20720893 is about 274.6646844190.

The spelling of 20720893 in words is "twenty million, seven hundred twenty thousand, eight hundred ninety-three".