20665281812 has 24 divisors (see below), whose sum is σ = 41731837056. Its totient is φ = 8770562208.

The previous prime is 20665281779. The next prime is 20665281827. The reversal of 20665281812 is 21818256602.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 20665281812.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3579863 + ... + 3585630.

It is an arithmetic number, because the mean of its divisors is an integer number (1738826544).

Almost surely, 2^20665281812 is an apocalyptic number.

It is an amenable number.

20665281812 is an abundant number, since it is smaller than the sum of its proper divisors (21066555244).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20665281812 is a wasteful number, since it uses less digits than its factorization.

20665281812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7165607 (or 7165605 counting only the distinct ones).

The product of its (nonzero) digits is 92160, while the sum is 41.

The spelling of 20665281812 in words is "twenty billion, six hundred sixty-five million, two hundred eighty-one thousand, eight hundred twelve".