20938705 has 4 divisors (see below), whose sum is σ = 25126452. Its totient is φ = 16750960.

The previous prime is 20938693. The next prime is 20938739. The reversal of 20938705 is 50783902.

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 4422609 + 16516096 = 2103^2 + 4064^2 .

It is not a de Polignac number, because 20938705 - 2⁹ = 20938193 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2093866 + ... + 2093875.

It is an arithmetic number, because the mean of its divisors is an integer number (6281613).

Almost surely, 2^20938705 is an apocalyptic number.

It is an amenable number.

20938705 is a deficient number, since it is larger than the sum of its proper divisors (4187747).

20938705 is an equidigital number, since it uses as much as digits as its factorization.

20938705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4187746.

The product of its (nonzero) digits is 15120, while the sum is 34.

The square root of 20938705 is about 4575.8829749022. The cubic root of 20938705 is about 275.6237302471.

The spelling of 20938705 in words is "twenty million, nine hundred thirty-eight thousand, seven hundred five".