20768883517 has 2 divisors, whose sum is σ = 20768883518. Its totient is φ = 20768883516.

The previous prime is 20768883503. The next prime is 20768883529. The reversal of 20768883517 is 71538886702.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 13431419236 + 7337464281 = 115894^2 + 85659^2 .

It is a cyclic number.

It is not a de Polignac number, because 20768883517 - 2¹⁹ = 20768359229 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20768883587) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10384441758 + 10384441759.

It is an arithmetic number, because the mean of its divisors is an integer number (10384441759).

Almost surely, 2^20768883517 is an apocalyptic number.

It is an amenable number.

20768883517 is a deficient number, since it is larger than the sum of its proper divisors (1).

20768883517 is an equidigital number, since it uses as much as digits as its factorization.

20768883517 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4515840, while the sum is 55.

The spelling of 20768883517 in words is "twenty billion, seven hundred sixty-eight million, eight hundred eighty-three thousand, five hundred seventeen".