20797728 has 48 divisors (see below), whose sum is σ = 62395200. Its totient is φ = 5942016.

The previous prime is 20797687. The next prime is 20797729. The reversal of 20797728 is 82779702.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a self number, because there is not a number n which added to its sum of digits gives 20797728.

It is not an unprimeable number, because it can be changed into a prime (20797729) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14803 + ... + 16146.

It is an arithmetic number, because the mean of its divisors is an integer number (1299900).

Almost surely, 2^20797728 is an apocalyptic number.

20797728 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20797728 is an abundant number, since it is smaller than the sum of its proper divisors (41597472).

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

20797728 is a wasteful number, since it uses less digits than its factorization.

20797728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30969 (or 30961 counting only the distinct ones).

The product of its (nonzero) digits is 98784, while the sum is 42.

The square root of 20797728 is about 4560.4526091168. The cubic root of 20797728 is about 275.0037597282.

It can be divided in two parts, 2079772 and 8, that added together give a triangular number (2079780 = T₂₀₃₉).

The spelling of 20797728 in words is "twenty million, seven hundred ninety-seven thousand, seven hundred twenty-eight".