20726305 has 4 divisors (see below), whose sum is σ = 24871572. Its totient is φ = 16581040.

The previous prime is 20726291. The next prime is 20726317. The reversal of 20726305 is 50362702.

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 12194064 + 8532241 = 3492^2 + 2921^2 .

It is not a de Polignac number, because 20726305 - 2⁷ = 20726177 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20726305.

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, 2072626 + ... + 2072635.

It is an arithmetic number, because the mean of its divisors is an integer number (6217893).

Almost surely, 2^20726305 is an apocalyptic number.

It is an amenable number.

20726305 is a deficient number, since it is larger than the sum of its proper divisors (4145267).

20726305 is an equidigital number, since it uses as much as digits as its factorization.

20726305 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4145266.

The product of its (nonzero) digits is 2520, while the sum is 25.

The square root of 20726305 is about 4552.6151825077. The cubic root of 20726305 is about 274.6885951625.

The spelling of 20726305 in words is "twenty million, seven hundred twenty-six thousand, three hundred five".