20729769997 has 2 divisors, whose sum is σ = 20729769998. Its totient is φ = 20729769996.

The previous prime is 20729769919. The next prime is 20729770001. The reversal of 20729769997 is 79996792702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19986607876 + 743162121 = 141374^2 + 27261^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20729769997 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20729769097) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10364884998 + 10364884999.

It is an arithmetic number, because the mean of its divisors is an integer number (10364884999).

Almost surely, 2^20729769997 is an apocalyptic number.

It is an amenable number.

20729769997 is a deficient number, since it is larger than the sum of its proper divisors (1).

20729769997 is an equidigital number, since it uses as much as digits as its factorization.

20729769997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54010152, while the sum is 67.

The spelling of 20729769997 in words is "twenty billion, seven hundred twenty-nine million, seven hundred sixty-nine thousand, nine hundred ninety-seven".