20199605 has 8 divisors (see below), whose sum is σ = 24286392. Its totient is φ = 16128448.

The previous prime is 20199583. The next prime is 20199617. The reversal of 20199605 is 50699102.

It can be written as a sum of positive squares in 4 ways, for example, as 786769 + 19412836 = 887^2 + 4406^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20199605 - 2¹⁸ = 19937461 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 7 ways as a sum of consecutive naturals, for example, 842 + ... + 6411.

It is an arithmetic number, because the mean of its divisors is an integer number (3035799).

Almost surely, 2^20199605 is an apocalyptic number.

It is an amenable number.

20199605 is a deficient number, since it is larger than the sum of its proper divisors (4086787).

20199605 is an equidigital number, since it uses as much as digits as its factorization.

20199605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7815.

The product of its (nonzero) digits is 4860, while the sum is 32.

The square root of 20199605 is about 4494.3970674608. The cubic root of 20199605 is about 272.3417929686.

The spelling of 20199605 in words is "twenty million, one hundred ninety-nine thousand, six hundred five".