20767718173 has 2 divisors, whose sum is σ = 20767718174. Its totient is φ = 20767718172.

The previous prime is 20767718131. The next prime is 20767718203. The reversal of 20767718173 is 37181776702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17170957444 + 3596760729 = 131038^2 + 59973^2 .

It is a cyclic number.

It is not a de Polignac number, because 20767718173 - 2¹³ = 20767709981 is a prime.

It is a super-2 number, since 2×20767718173² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20767718473) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10383859086 + 10383859087.

It is an arithmetic number, because the mean of its divisors is an integer number (10383859087).

Almost surely, 2^20767718173 is an apocalyptic number.

It is an amenable number.

20767718173 is a deficient number, since it is larger than the sum of its proper divisors (1).

20767718173 is an equidigital number, since it uses as much as digits as its factorization.

20767718173 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 691488, while the sum is 49.

The spelling of 20767718173 in words is "twenty billion, seven hundred sixty-seven million, seven hundred eighteen thousand, one hundred seventy-three".