21040741 has 2 divisors, whose sum is σ = 21040742. Its totient is φ = 21040740.

The previous prime is 21040729. The next prime is 21040759. The reversal of 21040741 is 14704012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20520900 + 519841 = 4530^2 + 721^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21040741 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21040541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10520370 + 10520371.

It is an arithmetic number, because the mean of its divisors is an integer number (10520371).

Almost surely, 2^21040741 is an apocalyptic number.

It is an amenable number.

21040741 is a deficient number, since it is larger than the sum of its proper divisors (1).

21040741 is an equidigital number, since it uses as much as digits as its factorization.

21040741 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 21040741 is about 4587.0187485991. The cubic root of 21040741 is about 276.0707171939.

Adding to 21040741 its reverse (14704012), we get a palindrome (35744753).

The spelling of 21040741 in words is "twenty-one million, forty thousand, seven hundred forty-one".