20897243 has 2 divisors, whose sum is σ = 20897244. Its totient is φ = 20897242.

The previous prime is 20897237. The next prime is 20897263. The reversal of 20897243 is 34279802.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20897243 is a prime.

It is not a weakly prime, because it can be changed into another prime (20897213) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10448621 + 10448622.

It is an arithmetic number, because the mean of its divisors is an integer number (10448622).

Almost surely, 2^20897243 is an apocalyptic number.

20897243 is a deficient number, since it is larger than the sum of its proper divisors (1).

20897243 is an equidigital number, since it uses as much as digits as its factorization.

20897243 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24192, while the sum is 35.

The square root of 20897243 is about 4571.3502381681. The cubic root of 20897243 is about 275.4416836108.

The spelling of 20897243 in words is "twenty million, eight hundred ninety-seven thousand, two hundred forty-three".