20138769565 has 4 divisors (see below), whose sum is σ = 24166523484. Its totient is φ = 16111015648.

The previous prime is 20138769559. The next prime is 20138769583. The reversal of 20138769565 is 56596783102.

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 7144137529 + 12994632036 = 84523^2 + 113994^2 .

It is a cyclic number.

It is not a de Polignac number, because 20138769565 - 2⁵ = 20138769533 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2013876952 + ... + 2013876961.

It is an arithmetic number, because the mean of its divisors is an integer number (6041630871).

Almost surely, 2^20138769565 is an apocalyptic number.

It is an amenable number.

20138769565 is a deficient number, since it is larger than the sum of its proper divisors (4027753919).

20138769565 is an equidigital number, since it uses as much as digits as its factorization.

20138769565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4027753918.

The product of its (nonzero) digits is 2721600, while the sum is 52.

The spelling of 20138769565 in words is "twenty billion, one hundred thirty-eight million, seven hundred sixty-nine thousand, five hundred sixty-five".