20728122 has 8 divisors (see below), whose sum is σ = 41456256. Its totient is φ = 6909372.

The previous prime is 20728121. The next prime is 20728133. The reversal of 20728122 is 22182702.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

20728122 is an admirable number.

It is a junction number, because it is equal to n+sod(n) for n = 20728092 and 20728101.

It is not an unprimeable number, because it can be changed into a prime (20728121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1727338 + ... + 1727349.

It is an arithmetic number, because the mean of its divisors is an integer number (5182032).

Almost surely, 2^20728122 is an apocalyptic number.

20728122 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

20728122 is a wasteful number, since it uses less digits than its factorization.

20728122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3454692.

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 20728122 is about 4552.8147337664. The cubic root of 20728122 is about 274.6966219123.

The spelling of 20728122 in words is "twenty million, seven hundred twenty-eight thousand, one hundred twenty-two".