20780621713 has 2 divisors, whose sum is σ = 20780621714. Its totient is φ = 20780621712.

The previous prime is 20780621707. The next prime is 20780621737. The reversal of 20780621713 is 31712608702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19246567824 + 1534053889 = 138732^2 + 39167^2 .

It is a cyclic number.

It is not a de Polignac number, because 20780621713 - 2⁵ = 20780621681 is a prime.

It is not a weakly prime, because it can be changed into another prime (20780621413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10390310856 + 10390310857.

It is an arithmetic number, because the mean of its divisors is an integer number (10390310857).

Almost surely, 2^20780621713 is an apocalyptic number.

It is an amenable number.

20780621713 is a deficient number, since it is larger than the sum of its proper divisors (1).

20780621713 is an equidigital number, since it uses as much as digits as its factorization.

20780621713 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 28224, while the sum is 37.

The spelling of 20780621713 in words is "twenty billion, seven hundred eighty million, six hundred twenty-one thousand, seven hundred thirteen".