20559609 has 32 divisors (see below), whose sum is σ = 35060480. Its totient is φ = 11664000.

The previous prime is 20559607. The next prime is 20559611. The reversal of 20559609 is 90695502.

It is an interprime number because it is at equal distance from previous prime (20559607) and next prime (20559611).

It is not a de Polignac number, because 20559609 - 2¹ = 20559607 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20559607) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 33909 + ... + 34509.

It is an arithmetic number, because the mean of its divisors is an integer number (1095640).

Almost surely, 2^20559609 is an apocalyptic number.

It is an amenable number.

20559609 is a deficient number, since it is larger than the sum of its proper divisors (14500871).

20559609 is a wasteful number, since it uses less digits than its factorization.

20559609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 798 (or 792 counting only the distinct ones).

The product of its (nonzero) digits is 24300, while the sum is 36.

The square root of 20559609 is about 4534.2705036202. The cubic root of 20559609 is about 273.9501969617.

It can be divided in two parts, 2055 and 9609, that added together give a square (11664 = 108²).

The spelling of 20559609 in words is "twenty million, five hundred fifty-nine thousand, six hundred nine".