20665532553 has 8 divisors (see below), whose sum is σ = 27706276416. Its totient is φ = 13700905200.

The previous prime is 20665532479. The next prime is 20665532557. The reversal of 20665532553 is 35523556602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20665532553 - 2⁸ = 20665532297 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20665532557) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19028493 + ... + 19029578.

It is an arithmetic number, because the mean of its divisors is an integer number (3463284552).

Almost surely, 2^20665532553 is an apocalyptic number.

It is an amenable number.

20665532553 is a deficient number, since it is larger than the sum of its proper divisors (7040743863).

20665532553 is a wasteful number, since it uses less digits than its factorization.

20665532553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38058255.

The product of its (nonzero) digits is 810000, while the sum is 42.

The spelling of 20665532553 in words is "twenty billion, six hundred sixty-five million, five hundred thirty-two thousand, five hundred fifty-three".