20665144423 has 32 divisors (see below), whose sum is σ = 26680296960. Its totient is φ = 15531384960.

The previous prime is 20665144387. The next prime is 20665144457. The reversal of 20665144423 is 32444156602.

It is not a de Polignac number, because 20665144423 - 2²¹ = 20663047271 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20665144523) 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, 2436436 + ... + 2444902.

It is an arithmetic number, because the mean of its divisors is an integer number (833759280).

Almost surely, 2^20665144423 is an apocalyptic number.

20665144423 is a deficient number, since it is larger than the sum of its proper divisors (6015152537).

20665144423 is a wasteful number, since it uses less digits than its factorization.

20665144423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9607.

The product of its (nonzero) digits is 138240, while the sum is 37.

The spelling of 20665144423 in words is "twenty billion, six hundred sixty-five million, one hundred forty-four thousand, four hundred twenty-three".