20628705 has 16 divisors (see below), whose sum is σ = 33459840. Its totient is φ = 10850688.

The previous prime is 20628683. The next prime is 20628709. The reversal of 20628705 is 50782602.

It is not a de Polignac number, because 20628705 - 2¹¹ = 20626657 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20628709) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8325 + ... + 10514.

It is an arithmetic number, because the mean of its divisors is an integer number (2091240).

Almost surely, 2^20628705 is an apocalyptic number.

It is an amenable number.

20628705 is a deficient number, since it is larger than the sum of its proper divisors (12831135).

20628705 is a wasteful number, since it uses less digits than its factorization.

20628705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18920.

The product of its (nonzero) digits is 6720, while the sum is 30.

The square root of 20628705 is about 4541.8834199041. The cubic root of 20628705 is about 274.2567478169.

The spelling of 20628705 in words is "twenty million, six hundred twenty-eight thousand, seven hundred five".