20500397 has 2 divisors, whose sum is σ = 20500398. Its totient is φ = 20500396.

The previous prime is 20500387. The next prime is 20500423. The reversal of 20500397 is 79300502.

It is an a-pointer prime, because the next prime (20500423) can be obtained adding 20500397 to its sum of digits (26).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 11703241 + 8797156 = 3421^2 + 2966^2 .

It is a cyclic number.

It is not a de Polignac number, because 20500397 - 2²⁰ = 19451821 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20500357) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10250198 + 10250199.

It is an arithmetic number, because the mean of its divisors is an integer number (10250199).

Almost surely, 2^20500397 is an apocalyptic number.

It is an amenable number.

20500397 is a deficient number, since it is larger than the sum of its proper divisors (1).

20500397 is an equidigital number, since it uses as much as digits as its factorization.

20500397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1890, while the sum is 26.

The square root of 20500397 is about 4527.7364101723. The cubic root of 20500397 is about 273.6869504443.

Adding to 20500397 its reverse (79300502), we get a palindrome (99800899).

The spelling of 20500397 in words is "twenty million, five hundred thousand, three hundred ninety-seven".