20785965663 has 4 divisors (see below), whose sum is σ = 27714620888. Its totient is φ = 13857310440.

The previous prime is 20785965647. The next prime is 20785965679. The reversal of 20785965663 is 36656958702.

It is a happy number.

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

It is an interprime number because it is at equal distance from previous prime (20785965647) and next prime (20785965679).

It is not a de Polignac number, because 20785965663 - 2⁴ = 20785965647 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20785965163) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3464327608 + ... + 3464327613.

It is an arithmetic number, because the mean of its divisors is an integer number (6928655222).

Almost surely, 2^20785965663 is an apocalyptic number.

20785965663 is a deficient number, since it is larger than the sum of its proper divisors (6928655225).

20785965663 is an equidigital number, since it uses as much as digits as its factorization.

20785965663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6928655224.

The product of its (nonzero) digits is 16329600, while the sum is 57.

The spelling of 20785965663 in words is "twenty billion, seven hundred eighty-five million, nine hundred sixty-five thousand, six hundred sixty-three".