20889009566 has 4 divisors (see below), whose sum is σ = 31333514352. Its totient is φ = 10444504782.

The previous prime is 20889009553. The next prime is 20889009569. The reversal of 20889009566 is 66590098802.

It is a happy number.

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

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20889009569) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5222252390 + ... + 5222252393.

It is an arithmetic number, because the mean of its divisors is an integer number (7833378588).

Almost surely, 2^20889009566 is an apocalyptic number.

20889009566 is a deficient number, since it is larger than the sum of its proper divisors (10444504786).

20889009566 is a wasteful number, since it uses less digits than its factorization.

20889009566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10444504785.

The product of its (nonzero) digits is 1866240, while the sum is 53.

The spelling of 20889009566 in words is "twenty billion, eight hundred eighty-nine million, nine thousand, five hundred sixty-six".