20687593 has 2 divisors, whose sum is σ = 20687594. Its totient is φ = 20687592.

The previous prime is 20687591. The next prime is 20687617. The reversal of 20687593 is 39578602.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 20313049 + 374544 = 4507^2 + 612^2 .

It is a cyclic number.

It is not a de Polignac number, because 20687593 - 2¹ = 20687591 is a prime.

Together with 20687591, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (20687591) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10343796 + 10343797.

It is an arithmetic number, because the mean of its divisors is an integer number (10343797).

Almost surely, 2^20687593 is an apocalyptic number.

It is an amenable number.

20687593 is a deficient number, since it is larger than the sum of its proper divisors (1).

20687593 is an equidigital number, since it uses as much as digits as its factorization.

20687593 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 90720, while the sum is 40.

The square root of 20687593 is about 4548.3615731382. The cubic root of 20687593 is about 274.5174700755.

The spelling of 20687593 in words is "twenty million, six hundred eighty-seven thousand, five hundred ninety-three".