20820968 has 32 divisors (see below), whose sum is σ = 44909760. Its totient is φ = 8864640.

The previous prime is 20820967. The next prime is 20820977. The reversal of 20820968 is 86902802.

It is a Cunningham number, because it is equal to 4563²-1.

It is not an unprimeable number, because it can be changed into a prime (20820967) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7988 + ... + 10268.

It is an arithmetic number, because the mean of its divisors is an integer number (1403430).

Almost surely, 2^20820968 is an apocalyptic number.

20820968 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20820968 is an abundant number, since it is smaller than the sum of its proper divisors (24088792).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20820968 is a wasteful number, since it uses less digits than its factorization.

20820968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2457 (or 2453 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 35.

The square root of 20820968 is about 4562.9998904230. Note that the first 3 decimals coincide. The cubic root of 20820968 is about 275.1061540590.

The spelling of 20820968 in words is "twenty million, eight hundred twenty thousand, nine hundred sixty-eight".