20726181 has 24 divisors (see below), whose sum is σ = 34369920. Its totient is φ = 11789856.

The previous prime is 20726177. The next prime is 20726183. The reversal of 20726181 is 18162702.

It is not a de Polignac number, because 20726181 - 2² = 20726177 is a prime.

It is a super-2 number, since 2×20726181² = 859149157689522, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20726183) 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 23 ways as a sum of consecutive naturals, for example, 16336 + ... + 17558.

It is an arithmetic number, because the mean of its divisors is an integer number (1432080).

Almost surely, 2^20726181 is an apocalyptic number.

20726181 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20726181 is a deficient number, since it is larger than the sum of its proper divisors (13643739).

20726181 is a wasteful number, since it uses less digits than its factorization.

20726181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1505 (or 1502 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 20726181 is about 4552.6015639412. The cubic root of 20726181 is about 274.6880473650.

Adding to 20726181 its reverse (18162702), we get a palindrome (38888883).

The spelling of 20726181 in words is "twenty million, seven hundred twenty-six thousand, one hundred eighty-one".