20322720 has 144 divisors (see below), whose sum is σ = 75714912. Its totient is φ = 4922880.

The previous prime is 20322719. The next prime is 20322733. The reversal of 20322720 is 2722302.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 20322693 and 20322702.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15199 + ... + 16481.

It is an arithmetic number, because the mean of its divisors is an integer number (525798).

Almost surely, 2^20322720 is an apocalyptic number.

20322720 is a gapful number since it is divisible by the number (20) 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 20322720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (37857456).

20322720 is an abundant number, since it is smaller than the sum of its proper divisors (55392192).

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

20322720 is a wasteful number, since it uses less digits than its factorization.

20322720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1315 (or 1304 counting only the distinct ones).

The product of its (nonzero) digits is 336, while the sum is 18.

The square root of 20322720 is about 4508.0727589514. The cubic root of 20322720 is about 272.8939732375.

The spelling of 20322720 in words is "twenty million, three hundred twenty-two thousand, seven hundred twenty".