20772905 has 4 divisors (see below), whose sum is σ = 24927492. Its totient is φ = 16618320.

The previous prime is 20772901. The next prime is 20772911. The reversal of 20772905 is 50927702.

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 12524521 + 8248384 = 3539^2 + 2872^2 .

It is not a de Polignac number, because 20772905 - 2² = 20772901 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20772901) 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, 2077286 + ... + 2077295.

It is an arithmetic number, because the mean of its divisors is an integer number (6231873).

Almost surely, 2^20772905 is an apocalyptic number.

It is an amenable number.

20772905 is a deficient number, since it is larger than the sum of its proper divisors (4154587).

20772905 is an equidigital number, since it uses as much as digits as its factorization.

20772905 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4154586.

The product of its (nonzero) digits is 8820, while the sum is 32.

The square root of 20772905 is about 4557.7302465153. The cubic root of 20772905 is about 274.8943064904.

The spelling of 20772905 in words is "twenty million, seven hundred seventy-two thousand, nine hundred five".