20650997 has 2 divisors, whose sum is σ = 20650998. Its totient is φ = 20650996.

The previous prime is 20650979. The next prime is 20651021. The reversal of 20650997 is 79905602.

Together with previous prime (20650979) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11566801 + 9084196 = 3401^2 + 3014^2 .

It is a cyclic number.

It is not a de Polignac number, because 20650997 - 2¹⁰ = 20649973 is a prime.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20650997.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20655997) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10325498 + 10325499.

It is an arithmetic number, because the mean of its divisors is an integer number (10325499).

Almost surely, 2^20650997 is an apocalyptic number.

It is an amenable number.

20650997 is a deficient number, since it is larger than the sum of its proper divisors (1).

20650997 is an equidigital number, since it uses as much as digits as its factorization.

20650997 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 34020, while the sum is 38.

The square root of 20650997 is about 4544.3368052995. The cubic root of 20650997 is about 274.3555022873.

The spelling of 20650997 in words is "twenty million, six hundred fifty thousand, nine hundred ninety-seven".