20593681 has 4 divisors (see below), whose sum is σ = 21805092. Its totient is φ = 19382272.

The previous prime is 20593673. The next prime is 20593687. The reversal of 20593681 is 18639502.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 6275025 + 14318656 = 2505^2 + 3784^2 .

It is a cyclic number.

It is not a de Polignac number, because 20593681 - 2³ = 20593673 is a prime.

It is a super-2 number, since 2×20593681² = 848199394259522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20593687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 605680 + ... + 605713.

It is an arithmetic number, because the mean of its divisors is an integer number (5451273).

Almost surely, 2^20593681 is an apocalyptic number.

It is an amenable number.

20593681 is a deficient number, since it is larger than the sum of its proper divisors (1211411).

20593681 is a wasteful number, since it uses less digits than its factorization.

20593681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1211410.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 20593681 is about 4538.0261127499. The cubic root of 20593681 is about 274.1014462654.

The spelling of 20593681 in words is "twenty million, five hundred ninety-three thousand, six hundred eighty-one".