20657323997 has 2 divisors, whose sum is σ = 20657323998. Its totient is φ = 20657323996.

The previous prime is 20657323979. The next prime is 20657324003. The reversal of 20657323997 is 79932375602.

Together with previous prime (20657323979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 19402818436 + 1254505561 = 139294^2 + 35419^2 .

It is a cyclic number.

It is not a de Polignac number, because 20657323997 - 2¹² = 20657319901 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20657320997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10328661998 + 10328661999.

It is an arithmetic number, because the mean of its divisors is an integer number (10328661999).

Almost surely, 2^20657323997 is an apocalyptic number.

It is an amenable number.

20657323997 is a deficient number, since it is larger than the sum of its proper divisors (1).

20657323997 is an equidigital number, since it uses as much as digits as its factorization.

20657323997 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4286520, while the sum is 53.

The spelling of 20657323997 in words is "twenty billion, six hundred fifty-seven million, three hundred twenty-three thousand, nine hundred ninety-seven".