20928653 has 4 divisors (see below), whose sum is σ = 20948928. Its totient is φ = 20908380.

The previous prime is 20928647. The next prime is 20928679. The reversal of 20928653 is 35682902.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20928653 - 2⁴ = 20928637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20928353) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8501 + ... + 10682.

It is an arithmetic number, because the mean of its divisors is an integer number (5237232).

Almost surely, 2^20928653 is an apocalyptic number.

It is an amenable number.

20928653 is a deficient number, since it is larger than the sum of its proper divisors (20275).

20928653 is a wasteful number, since it uses less digits than its factorization.

20928653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20274.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 20928653 is about 4574.7844757977. The cubic root of 20928653 is about 275.5796171528.

The spelling of 20928653 in words is "twenty million, nine hundred twenty-eight thousand, six hundred fifty-three".