20779519357 has 2 divisors, whose sum is σ = 20779519358. Its totient is φ = 20779519356.

The previous prime is 20779519331. The next prime is 20779519363. The reversal of 20779519357 is 75391597702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15498009081 + 5281510276 = 124491^2 + 72674^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20779519357 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20779519298 and 20779519307.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20779519757) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10389759678 + 10389759679.

It is an arithmetic number, because the mean of its divisors is an integer number (10389759679).

Almost surely, 2^20779519357 is an apocalyptic number.

It is an amenable number.

20779519357 is a deficient number, since it is larger than the sum of its proper divisors (1).

20779519357 is an equidigital number, since it uses as much as digits as its factorization.

20779519357 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4167450, while the sum is 55.

The spelling of 20779519357 in words is "twenty billion, seven hundred seventy-nine million, five hundred nineteen thousand, three hundred fifty-seven".