20819617 has 12 divisors (see below), whose sum is σ = 25766400. Its totient is φ = 16471728.

The previous prime is 20819563. The next prime is 20819629. The reversal of 20819617 is 71691802.

It is a happy number.

It is not a de Polignac number, because 20819617 - 2¹⁹ = 20295329 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20819657) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7617 + ... + 9982.

It is an arithmetic number, because the mean of its divisors is an integer number (2147200).

Almost surely, 2^20819617 is an apocalyptic number.

It is an amenable number.

20819617 is a deficient number, since it is larger than the sum of its proper divisors (4946783).

20819617 is a wasteful number, since it uses less digits than its factorization.

20819617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17632 (or 17619 counting only the distinct ones).

The product of its (nonzero) digits is 6048, while the sum is 34.

The square root of 20819617 is about 4562.8518494468. The cubic root of 20819617 is about 275.1002037040.

The spelling of 20819617 in words is "twenty million, eight hundred nineteen thousand, six hundred seventeen".