20797218 has 96 divisors (see below), whose sum is σ = 51996672. Its totient is φ = 5961600.

The previous prime is 20797207. The next prime is 20797223. The reversal of 20797218 is 81279702.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 340908 + ... + 340968.

It is an arithmetic number, because the mean of its divisors is an integer number (541632).

Almost surely, 2^20797218 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20797218, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25998336).

20797218 is an abundant number, since it is smaller than the sum of its proper divisors (31199454).

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

20797218 is a wasteful number, since it uses less digits than its factorization.

20797218 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160 (or 157 counting only the distinct ones).

The product of its (nonzero) digits is 14112, while the sum is 36.

The square root of 20797218 is about 4560.3966932713. The cubic root of 20797218 is about 275.0015118374.

The spelling of 20797218 in words is "twenty million, seven hundred ninety-seven thousand, two hundred eighteen".