20665263671 has 16 divisors (see below), whose sum is σ = 23250296160. Its totient is φ = 18235459200.

The previous prime is 20665263659. The next prime is 20665263739. The reversal of 20665263671 is 17636256602.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 20665263671 - 2¹⁰ = 20665262647 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20665263601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 233285 + ... + 309438.

It is an arithmetic number, because the mean of its divisors is an integer number (1453143510).

Almost surely, 2^20665263671 is an apocalyptic number.

20665263671 is a deficient number, since it is larger than the sum of its proper divisors (2585032489).

20665263671 is a wasteful number, since it uses less digits than its factorization.

20665263671 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 542866.

The product of its (nonzero) digits is 544320, while the sum is 44.

The spelling of 20665263671 in words is "twenty billion, six hundred sixty-five million, two hundred sixty-three thousand, six hundred seventy-one".