20897968 has 80 divisors (see below), whose sum is σ = 51552256. Its totient is φ = 7983360.

The previous prime is 20897923. The next prime is 20897969. The reversal of 20897968 is 86979802.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (20897969) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 44905 + ... + 45367.

Almost surely, 2^20897968 is an apocalyptic number.

20897968 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20897968, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25776128).

20897968 is an abundant number, since it is smaller than the sum of its proper divisors (30654288).

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

20897968 is a wasteful number, since it uses less digits than its factorization.

20897968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522 (or 516 counting only the distinct ones).

The product of its (nonzero) digits is 435456, while the sum is 49.

The square root of 20897968 is about 4571.4295357142. The cubic root of 20897968 is about 275.4448689259. Note that the first 3 decimals are identical.

The spelling of 20897968 in words is "twenty million, eight hundred ninety-seven thousand, nine hundred sixty-eight".