20683747647 has 12 divisors (see below), whose sum is σ = 29884886304. Its totient is φ = 13785305760.

The previous prime is 20683747621. The next prime is 20683747673. The reversal of 20683747647 is 74674738602.

20683747647 is a `hidden beast` number, since 206 + 8 + 374 + 7 + 64 + 7 = 666.

It is an interprime number because it is at equal distance from previous prime (20683747621) and next prime (20683747673).

It is not a de Polignac number, because 20683747647 - 2⁶ = 20683747583 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a junction number, because it is equal to n+sod(n) for n = 20683747593 and 20683747602.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20683747687) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 287479 + ... + 352152.

It is an arithmetic number, because the mean of its divisors is an integer number (2490407192).

Almost surely, 2^20683747647 is an apocalyptic number.

20683747647 is a deficient number, since it is larger than the sum of its proper divisors (9201138657).

20683747647 is a wasteful number, since it uses less digits than its factorization.

20683747647 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 643230 (or 643227 counting only the distinct ones).

The product of its (nonzero) digits is 9483264, while the sum is 54.

The spelling of 20683747647 in words is "twenty billion, six hundred eighty-three million, seven hundred forty-seven thousand, six hundred forty-seven".