20736491 has 2 divisors, whose sum is σ = 20736492. Its totient is φ = 20736490.

The previous prime is 20736461. The next prime is 20736509. The reversal of 20736491 is 19463702.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20736491 - 2¹⁰ = 20735467 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20736431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10368245 + 10368246.

It is an arithmetic number, because the mean of its divisors is an integer number (10368246).

Almost surely, 2^20736491 is an apocalyptic number.

20736491 is a deficient number, since it is larger than the sum of its proper divisors (1).

20736491 is an equidigital number, since it uses as much as digits as its factorization.

20736491 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9072, while the sum is 32.

The square root of 20736491 is about 4553.7337427654. The cubic root of 20736491 is about 274.7335866166.

The spelling of 20736491 in words is "twenty million, seven hundred thirty-six thousand, four hundred ninety-one".