20897543 has 2 divisors, whose sum is σ = 20897544. Its totient is φ = 20897542.

The previous prime is 20897533. The next prime is 20897551. The reversal of 20897543 is 34579802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20897543 - 2⁶ = 20897479 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20897497 and 20897506.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20897533) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10448771 + 10448772.

It is an arithmetic number, because the mean of its divisors is an integer number (10448772).

Almost surely, 2^20897543 is an apocalyptic number.

20897543 is a deficient number, since it is larger than the sum of its proper divisors (1).

20897543 is an equidigital number, since it uses as much as digits as its factorization.

20897543 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 60480, while the sum is 38.

The square root of 20897543 is about 4571.3830511126. The cubic root of 20897543 is about 275.4430016811.

The spelling of 20897543 in words is "twenty million, eight hundred ninety-seven thousand, five hundred forty-three".