20783469557 has 2 divisors, whose sum is σ = 20783469558. Its totient is φ = 20783469556.

The previous prime is 20783469529. The next prime is 20783469569. The reversal of 20783469557 is 75596438702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16464482596 + 4318986961 = 128314^2 + 65719^2 .

It is a cyclic number.

It is not a de Polignac number, because 20783469557 - 2¹⁶ = 20783404021 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20783469757) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10391734778 + 10391734779.

It is an arithmetic number, because the mean of its divisors is an integer number (10391734779).

Almost surely, 2^20783469557 is an apocalyptic number.

It is an amenable number.

20783469557 is a deficient number, since it is larger than the sum of its proper divisors (1).

20783469557 is an equidigital number, since it uses as much as digits as its factorization.

20783469557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12700800, while the sum is 56.

The spelling of 20783469557 in words is "twenty billion, seven hundred eighty-three million, four hundred sixty-nine thousand, five hundred fifty-seven".