20897816 has 16 divisors (see below), whose sum is σ = 39467400. Its totient is φ = 10373184.

The previous prime is 20897801. The next prime is 20897819. The reversal of 20897816 is 61879802.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20897819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8285 + ... + 10508.

Almost surely, 2^20897816 is an apocalyptic number.

It is an amenable number.

20897816 is a deficient number, since it is larger than the sum of its proper divisors (18569584).

20897816 is a wasteful number, since it uses less digits than its factorization.

20897816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18938 (or 18934 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 41.

The square root of 20897816 is about 4571.4129106875. The cubic root of 20897816 is about 275.4442011142. Note that the first 3 decimals are identical.

The spelling of 20897816 in words is "twenty million, eight hundred ninety-seven thousand, eight hundred sixteen".