20897923 has 2 divisors, whose sum is σ = 20897924. Its totient is φ = 20897922.

The previous prime is 20897917. The next prime is 20897969. The reversal of 20897923 is 32979802.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20897923 - 2⁹ = 20897411 is a prime.

It is not a weakly prime, because it can be changed into another prime (20897983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10448961 + 10448962.

It is an arithmetic number, because the mean of its divisors is an integer number (10448962).

Almost surely, 2^20897923 is an apocalyptic number.

20897923 is a deficient number, since it is larger than the sum of its proper divisors (1).

20897923 is an equidigital number, since it uses as much as digits as its factorization.

20897923 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 54432, while the sum is 40.

The square root of 20897923 is about 4571.4246138376. The cubic root of 20897923 is about 275.4446712188. Note that the first 3 decimals are identical.

The spelling of 20897923 in words is "twenty million, eight hundred ninety-seven thousand, nine hundred twenty-three".