20655569 has 16 divisors (see below), whose sum is σ = 23656320. Its totient is φ = 17861760.

The previous prime is 20655563. The next prime is 20655619. The reversal of 20655569 is 96555602.

It is a cyclic number.

It is not a de Polignac number, because 20655569 - 2⁴ = 20655553 is a prime.

It is a super-2 number, since 2×20655569² = 853305061427522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20655563) 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, 22844 + ... + 23730.

It is an arithmetic number, because the mean of its divisors is an integer number (1478520).

Almost surely, 2^20655569 is an apocalyptic number.

20655569 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

20655569 is a deficient number, since it is larger than the sum of its proper divisors (3000751).

20655569 is a wasteful number, since it uses less digits than its factorization.

20655569 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1000.

The product of its (nonzero) digits is 81000, while the sum is 38.

The square root of 20655569 is about 4544.8398211598. The cubic root of 20655569 is about 274.3757476504.

The spelling of 20655569 in words is "twenty million, six hundred fifty-five thousand, five hundred sixty-nine".