20508493 has 2 divisors, whose sum is σ = 20508494. Its totient is φ = 20508492.

The previous prime is 20508473. The next prime is 20508503. The reversal of 20508493 is 39480502.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16752649 + 3755844 = 4093^2 + 1938^2 .

It is a cyclic number.

It is not a de Polignac number, because 20508493 - 2¹⁷ = 20377421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20508413) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10254246 + 10254247.

It is an arithmetic number, because the mean of its divisors is an integer number (10254247).

Almost surely, 2^20508493 is an apocalyptic number.

It is an amenable number.

20508493 is a deficient number, since it is larger than the sum of its proper divisors (1).

20508493 is an equidigital number, since it uses as much as digits as its factorization.

20508493 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 20508493 is about 4528.6303668990. The cubic root of 20508493 is about 273.7229737780.

Adding to 20508493 its reverse (39480502), we get a palindrome (59988995).

The spelling of 20508493 in words is "twenty million, five hundred eight thousand, four hundred ninety-three".