20731097 has 2 divisors, whose sum is σ = 20731098. Its totient is φ = 20731096.

The previous prime is 20731091. The next prime is 20731121. The reversal of 20731097 is 79013702.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10896601 + 9834496 = 3301^2 + 3136^2 .

It is a cyclic number.

It is not a de Polignac number, because 20731097 - 2¹⁸ = 20468953 is a prime.

It is not a weakly prime, because it can be changed into another prime (20731091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10365548 + 10365549.

It is an arithmetic number, because the mean of its divisors is an integer number (10365549).

Almost surely, 2^20731097 is an apocalyptic number.

It is an amenable number.

20731097 is a deficient number, since it is larger than the sum of its proper divisors (1).

20731097 is an equidigital number, since it uses as much as digits as its factorization.

20731097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2646, while the sum is 29.

The square root of 20731097 is about 4553.1414430039. The cubic root of 20731097 is about 274.7097632115.

Adding to 20731097 its reverse (79013702), we get a palindrome (99744799).

The spelling of 20731097 in words is "twenty million, seven hundred thirty-one thousand, ninety-seven".