20784428 has 24 divisors (see below), whose sum is σ = 42420000. Its totient is φ = 8907024.

The previous prime is 20784409. The next prime is 20784443. The reversal of 20784428 is 82448702.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6203 + ... + 8946.

It is an arithmetic number, because the mean of its divisors is an integer number (1767500).

Almost surely, 2^20784428 is an apocalyptic number.

20784428 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

20784428 is an abundant number, since it is smaller than the sum of its proper divisors (21635572).

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

20784428 is a wasteful number, since it uses less digits than its factorization.

20784428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15174 (or 15158 counting only the distinct ones).

The product of its (nonzero) digits is 28672, while the sum is 35.

The square root of 20784428 is about 4558.9941873181. The cubic root of 20784428 is about 274.9451262412.

It can be divided in two parts, 20784 and 428, that added together give a palindrome (21212).

The spelling of 20784428 in words is "twenty million, seven hundred eighty-four thousand, four hundred twenty-eight".