20769217765 has 4 divisors (see below), whose sum is σ = 24923061324. Its totient is φ = 16615374208.

The previous prime is 20769217739. The next prime is 20769217823. The reversal of 20769217765 is 56771296702.

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

It can be written as a sum of positive squares in 2 ways, for example, as 3669209476 + 17100008289 = 60574^2 + 130767^2 .

It is a cyclic number.

It is not a de Polignac number, because 20769217765 - 2¹⁷ = 20769086693 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2076921772 + ... + 2076921781.

It is an arithmetic number, because the mean of its divisors is an integer number (6230765331).

Almost surely, 2^20769217765 is an apocalyptic number.

It is an amenable number.

20769217765 is a deficient number, since it is larger than the sum of its proper divisors (4153843559).

20769217765 is an equidigital number, since it uses as much as digits as its factorization.

20769217765 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4153843558.

The product of its (nonzero) digits is 2222640, while the sum is 52.

The spelling of 20769217765 in words is "twenty billion, seven hundred sixty-nine million, two hundred seventeen thousand, seven hundred sixty-five".