20636665725 has 24 divisors (see below), whose sum is σ = 36743849632. Its totient is φ = 10159588800.

The previous prime is 20636665717. The next prime is 20636665747. The reversal of 20636665725 is 52756663602.

It is not a de Polignac number, because 20636665725 - 2³ = 20636665717 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 23 ways as a sum of consecutive naturals, for example, 10581931 + ... + 10583880.

Almost surely, 2^20636665725 is an apocalyptic number.

20636665725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20636665725 is a deficient number, since it is larger than the sum of its proper divisors (16107183907).

20636665725 is a wasteful number, since it uses less digits than its factorization.

20636665725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21165837 (or 21165832 counting only the distinct ones).

The product of its (nonzero) digits is 2721600, while the sum is 48.

The spelling of 20636665725 in words is "twenty billion, six hundred thirty-six million, six hundred sixty-five thousand, seven hundred twenty-five".