20628845 has 4 divisors (see below), whose sum is σ = 24754620. Its totient is φ = 16503072.

The previous prime is 20628823. The next prime is 20628859. The reversal of 20628845 is 54882602.

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 14645929 + 5982916 = 3827^2 + 2446^2 .

It is a cyclic number.

It is not a de Polignac number, because 20628845 - 2⁸ = 20628589 is a prime.

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, 2062880 + ... + 2062889.

It is an arithmetic number, because the mean of its divisors is an integer number (6188655).

Almost surely, 2^20628845 is an apocalyptic number.

It is an amenable number.

20628845 is a deficient number, since it is larger than the sum of its proper divisors (4125775).

20628845 is an equidigital number, since it uses as much as digits as its factorization.

20628845 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4125774.

The product of its (nonzero) digits is 30720, while the sum is 35.

The square root of 20628845 is about 4541.8988319865. The cubic root of 20628845 is about 274.2573682445.

The spelling of 20628845 in words is "twenty million, six hundred twenty-eight thousand, eight hundred forty-five".