20740261 has 2 divisors, whose sum is σ = 20740262. Its totient is φ = 20740260.

The previous prime is 20740259. The next prime is 20740297. The reversal of 20740261 is 16204702.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17589636 + 3150625 = 4194^2 + 1775^2 .

It is a cyclic number.

It is not a de Polignac number, because 20740261 - 2¹ = 20740259 is a prime.

Together with 20740259, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20740201) 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 as a sum of consecutive naturals, namely, 10370130 + 10370131.

It is an arithmetic number, because the mean of its divisors is an integer number (10370131).

Almost surely, 2^20740261 is an apocalyptic number.

It is an amenable number.

20740261 is a deficient number, since it is larger than the sum of its proper divisors (1).

20740261 is an equidigital number, since it uses as much as digits as its factorization.

20740261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 672, while the sum is 22.

The square root of 20740261 is about 4554.1476699817. The cubic root of 20740261 is about 274.7502349309.

Adding to 20740261 its reverse (16204702), we get a palindrome (36944963).

The spelling of 20740261 in words is "twenty million, seven hundred forty thousand, two hundred sixty-one".