20724081 has 32 divisors (see below), whose sum is σ = 33343488. Its totient is φ = 11193600.

The previous prime is 20724049. The next prime is 20724091. The reversal of 20724081 is 18042702.

It is not a de Polignac number, because 20724081 - 2⁵ = 20724049 is a prime.

It is a super-2 number, since 2×20724081² = 858975066589122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20724001) by changing a digit.

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 31 ways as a sum of consecutive naturals, for example, 51481 + ... + 51881.

It is an arithmetic number, because the mean of its divisors is an integer number (1041984).

Almost surely, 2^20724081 is an apocalyptic number.

20724081 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20724081 is a deficient number, since it is larger than the sum of its proper divisors (12619407).

20724081 is a wasteful number, since it uses less digits than its factorization.

20724081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 541.

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 20724081 is about 4552.3709207401. The cubic root of 20724081 is about 274.6787698176.

Adding to 20724081 its reverse (18042702), we get a palindrome (38766783).

The spelling of 20724081 in words is "twenty million, seven hundred twenty-four thousand, eighty-one".