20831428 has 12 divisors (see below), whose sum is σ = 36541120.
Its totient is φ = 10391112.
The previous prime is 20831323. The next prime is 20831533. The reversal of 20831428 is 82413802.
It is an interprime number because it is at equal distance from previous prime (20831323) and next prime (20831533).
It is a lonely number, since its distance to closest prime (20831533) sets a new record.
It is a junction number, because it is equal to n+sod(n) for n = 20831396 and 20831405.
It is an unprimeable number.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4176 + ... + 7687.
Almost surely, 220831428 is an apocalyptic number.
It is an amenable number.
20831428 is a deficient number, since it is larger than the sum of its proper divisors (15709692).
20831428 is a wasteful number, since it uses less digits than its factorization.
20831428 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 12306 (or 12304 counting only the distinct ones).
The product of its (nonzero) digits is 3072, while the sum is 28.
The square root of 20831428 is about 4564.1459222948.
The cubic root of 20831428 is about 275.1522154561.
The spelling of 20831428 in words is "twenty million, eight hundred thirty-one thousand, four hundred twenty-eight".