20689465 has 4 divisors (see below), whose sum is σ = 24827364. Its totient is φ = 16551568.

The previous prime is 20689457. The next prime is 20689469. The reversal of 20689465 is 56498602.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 5851561 + 14837904 = 2419^2 + 3852^2 .

It is a cyclic number.

It is not a de Polignac number, because 20689465 - 2³ = 20689457 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20689469) 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, 2068942 + ... + 2068951.

It is an arithmetic number, because the mean of its divisors is an integer number (6206841).

Almost surely, 2^20689465 is an apocalyptic number.

It is an amenable number.

20689465 is a deficient number, since it is larger than the sum of its proper divisors (4137899).

20689465 is an equidigital number, since it uses as much as digits as its factorization.

20689465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4137898.

The product of its (nonzero) digits is 103680, while the sum is 40.

The square root of 20689465 is about 4548.5673568718. The cubic root of 20689465 is about 274.5257500979.

The spelling of 20689465 in words is "twenty million, six hundred eighty-nine thousand, four hundred sixty-five".