20994605 has 4 divisors (see below), whose sum is σ = 25193532. Its totient is φ = 16795680.

The previous prime is 20994569. The next prime is 20994647. The reversal of 20994605 is 50649902.

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 4502884 + 16491721 = 2122^2 + 4061^2 .

It is not a de Polignac number, because 20994605 - 2⁸ = 20994349 is a prime.

It is a Duffinian number.

It is a congruent 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, 2099456 + ... + 2099465.

It is an arithmetic number, because the mean of its divisors is an integer number (6298383).

Almost surely, 2^20994605 is an apocalyptic number.

It is an amenable number.

20994605 is a deficient number, since it is larger than the sum of its proper divisors (4198927).

20994605 is an equidigital number, since it uses as much as digits as its factorization.

20994605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4198926.

The product of its (nonzero) digits is 19440, while the sum is 35.

The square root of 20994605 is about 4581.9870143858. The cubic root of 20994605 is about 275.8687895893.

The spelling of 20994605 in words is "twenty million, nine hundred ninety-four thousand, six hundred five".