20491824 has 20 divisors (see below), whose sum is σ = 52937336. Its totient is φ = 6830592.

The previous prime is 20491811. The next prime is 20491829. The reversal of 20491824 is 42819402.

It is a hoax number, since the sum of its digits (30) coincides with the sum of the digits of its distinct prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 20491791 and 20491800.

It is not an unprimeable number, because it can be changed into a prime (20491829) 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 3 ways as a sum of consecutive naturals, for example, 213409 + ... + 213504.

Almost surely, 2^20491824 is an apocalyptic number.

20491824 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

20491824 is an abundant number, since it is smaller than the sum of its proper divisors (32445512).

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

20491824 is a wasteful number, since it uses less digits than its factorization.

20491824 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 426924 (or 426918 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 30.

The square root of 20491824 is about 4526.7895908690. The cubic root of 20491824 is about 273.6487943479.

The spelling of 20491824 in words is "twenty million, four hundred ninety-one thousand, eight hundred twenty-four".