20831424 has 28 divisors (see below), whose sum is σ = 55116984. Its totient is φ = 6943744.

The previous prime is 20831323. The next prime is 20831533. The reversal of 20831424 is 42413802.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a lonely number, since its distance to closest prime (20831323) sets a new record.

It is a junction number, because it is equal to n+sod(n) for n = 20831394 and 20831403.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 54057 + ... + 54440.

Almost surely, 2^20831424 is an apocalyptic number.

20831424 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20831424 is an abundant number, since it is smaller than the sum of its proper divisors (34285560).

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

20831424 is a wasteful number, since it uses less digits than its factorization.

20831424 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108512 (or 108502 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 24.

The square root of 20831424 is about 4564.1454840967. The cubic root of 20831424 is about 275.1521978447.

The spelling of 20831424 in words is "twenty million, eight hundred thirty-one thousand, four hundred twenty-four".