20840893 has 4 divisors (see below), whose sum is σ = 20852028. Its totient is φ = 20829760.

The previous prime is 20840887. The next prime is 20840923. The reversal of 20840893 is 39804802.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 6980164 + 13860729 = 2642^2 + 3723^2 .

It is a cyclic number.

It is not a de Polignac number, because 20840893 - 2⁹ = 20840381 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20840873) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1996 + ... + 6757.

It is an arithmetic number, because the mean of its divisors is an integer number (5213007).

Almost surely, 2^20840893 is an apocalyptic number.

It is an amenable number.

20840893 is a deficient number, since it is larger than the sum of its proper divisors (11135).

20840893 is an equidigital number, since it uses as much as digits as its factorization.

20840893 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11134.

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 20840893 is about 4565.1826907584. The cubic root of 20840893 is about 275.1938820089.

The spelling of 20840893 in words is "twenty million, eight hundred forty thousand, eight hundred ninety-three".