20745181 has 2 divisors, whose sum is σ = 20745182. Its totient is φ = 20745180.

The previous prime is 20745161. The next prime is 20745191. The reversal of 20745181 is 18154702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12013156 + 8732025 = 3466^2 + 2955^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20745181 is a prime.

It is a super-2 number, since 2×20745181² = 860725069445522, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20745161) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10372590 + 10372591.

It is an arithmetic number, because the mean of its divisors is an integer number (10372591).

Almost surely, 2^20745181 is an apocalyptic number.

It is an amenable number.

20745181 is a deficient number, since it is larger than the sum of its proper divisors (1).

20745181 is an equidigital number, since it uses as much as digits as its factorization.

20745181 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2240, while the sum is 28.

The square root of 20745181 is about 4554.6878048885. The cubic root of 20745181 is about 274.7719586093.

Adding to 20745181 its reverse (18154702), we get a palindrome (38899883).

The spelling of 20745181 in words is "twenty million, seven hundred forty-five thousand, one hundred eighty-one".