20865497 has 2 divisors, whose sum is σ = 20865498. Its totient is φ = 20865496.

The previous prime is 20865473. The next prime is 20865541. The reversal of 20865497 is 79456802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13980121 + 6885376 = 3739^2 + 2624^2 .

It is a cyclic number.

It is not a de Polignac number, because 20865497 - 2²⁰ = 19816921 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20865197) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10432748 + 10432749.

It is an arithmetic number, because the mean of its divisors is an integer number (10432749).

Almost surely, 2^20865497 is an apocalyptic number.

It is an amenable number.

20865497 is a deficient number, since it is larger than the sum of its proper divisors (1).

20865497 is an equidigital number, since it uses as much as digits as its factorization.

20865497 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120960, while the sum is 41.

The square root of 20865497 is about 4567.8766401907. The cubic root of 20865497 is about 275.3021340487.

The spelling of 20865497 in words is "twenty million, eight hundred sixty-five thousand, four hundred ninety-seven".